San Francisco Sessions, 1972

I have been processing information from contracts filed at the American Federation of Musicians (AFM) Local No. 6 in San Francisco.

• San Francisco Sessions, 1967-1968
• San Francisco Sessions, 1969
• San Francisco Sessions, 1970
• San Francisco Sessions, 1971
• San Francisco Sessions, 1972

There is nothing representative about these – I have information on stuff that is a degree or two from Garcia, and a few other random tidbits of idiosyncratic interest to me. I post them mostly for future researchers who might be interested. (The six-digit numbers just reference my scans, so I can retrieve these as needed.) List after the jump.

San Francisco Sessions, 1970

**updated 8/10/2015, especially under heading D**
**update2 8/11, more, especially, in section D**
**updated 8/12, re-ordered sections (now goes from more micro and Jerrycentric to more macro (and less so)), also reworked some of section D, though not really many new words.**

I have been processing information from contracts filed at the American Federation of Musicians (AFM) Local No. 6 in San Francisco.

• San Francisco Sessions, 1967-1968
• San Francisco Sessions, 1969
• This is the 1970 iteration, with bonus features. For this one, I include the Garcia events. They are formatted in blue. There is one GD entry, which is formatted orange.
• San Francisco Sessions, 1971
• San Francisco Sessions, 1972 

Let me speak to (A) Garcia sessions; (B) Dead-related stuff,(C) other Garciaverse echoes, and (D) an analysis of what these contracts tell us about San Francisco Rock on film in 1970.

A. Info on some of Jerry's prolific 1970 studio work:

1. Materials around the iconic Paul Kantner/Jefferson Starship Blows Against the Empire (RCA LSP 4448 [SF 8163], November 1970) tip the possibility of Garcia working on "Mau Mau" (July 17 and 22), not currently given at Deaddisc. This material may have ended up on the cutting room floor. They also us to date his credited contributions to "Starship" (July 15, August 10-11) (LIA corrected me on earlier error, saying this was previously uncredited.)
2. The song "Old Man" pops up July 15 and August 10. I am assuming this is Covington's execrable "Whatever The Old Man Does (Is Always Right)", unreleased from the Jeffersons' Bark (Grunt FTR 1001, September 1971) sessions.
3. Brewer & Shipley, Tarkio (Kama Sutra 2024, February 1971): Deaddisc shows Garcia only on "Oh Mommy". The session paperwork also lists "50 States Of Freedom", hard to know if Garcia played on that one and/or if any material was used. There is one contract for two sessions, so my hunch is that there was one session for each song, and Jerry probably only attended one of the two. Who knows. The sessions were Friday, August 21, 1970 at 5pm and 9pm. Work on the record picks up again in October, but Garcia, still/again at Heider's, makes no further appearances.
4. Lamb, Cross Between (Warner Brothers WS 1920, 1971): Deaddisc says "Jerry Garcia plays on Flying (banjo), Flotation (pedal steel) and Reach High (pedal steel)" and notes "Garcia's contribution to this LP is not documented on the LP cover. There is simply a note on the back cover that says 'special thanks to Jerry Garcia', which has been interpreted as meaning Garcia played on the album. It has subsequently been confirmed by Walter Rapaport, the co-producer of the album, that Garcia played on Flying, Flotation and Reach High. The contribution to Flotation is only 4 notes." For what it's worth, the contract gives us time: Monday, October 5, 1970, in the afternoon.
5. Thanks to commenter runonguinness, I see that RCA buys some "Soul Fever" on Tuesday, October 6, 1970, eventually to appear on Papa John Creach's self-named Grunt record (FTR 1003, December 1971). ROG notes "it is credited to Papa John, Garcia, Rolie, Brown and Covington and it does sound like just one guitar". Deaddisc does show a Garcia credit, listing Papa John Creach - electric violin, Dave Brown - bass, Joey Covington - drums, Jerry Garcia - guitar, Gregg Rolie - organ). So I guess the really tantalizing question is whether Carlos Santana showed up, and he and Jerry played together. It's interesting to me that there are just about no instance of that particular shared studio, and the Shared Stage only came about post-Garcia's 1986 coma. A few months later, in a near-miss (as far as we know), Carlos was billed playing with Merl Saunders at the Matrix). In the alternative, some Carlos licks hit the cutting room floor.

B. The Grateful Dead Node

1. I found no 1970 GD contracts in the union records, which is a tragic shame. Might such materials exist in the Grateful Dead Archive?
2. The Planet Eart Rock and Roll Orchestra (PERRO) sessions at Wally Heider's included some Dead guys, though Phil Lesh is curiously absent from any of the paperwork I have seen. Bill Kreutzmann has an appealing looking session on July 29th with Paul Kantner and David Crosby), Mickey Hart makes a less-appealing-to-me Joey Covington-led one on September 2, 1970. That session, BTW, also seems more reliably to put Spencer Dryden in the New Riders' drum chair at the Matrix this night, but for some weird reason I have listed Hart. I assume this is my error?
3. Bob Weir makes the James and the Good Brothers sessions in December, also with Mickey.
4. Note the new studio "Alembic, Inc.", address 320 Judah Street in SF, late in the year. These are the earliest references I have found to that particular dba configuration.
5. There's a Grateful Dead film contract dated 10/2, with no performance date listed. The location is given as “remote locations at Family Dog, PHR". It was contracted by KQED (Bay Area Educational Television Association), under the moniker "San Francisco Rock". Under heading D below you'll find that end up concluding that this session transmogrified into the live broadcast from Winterland on October 4, 1970. I have more to say about this in section D, below.

C. A few quickies more on the margins of the Garciaverse:

1. PERRO at Heider's. QED.
2. Paul Kantner spent a lot of time in the studio, and the amount of studio time at Heider's paid out of RCA monies speaks to just how lucrative the Jeffersons' contracts really were. Doug Sahm (Mercury) and Joe McDonald (Vanguard) get a lot of time in, as well.
3. An awful lot of the PERRO contracts are AWOL, based on the comparison of the union files with, e.g., the metadata attached to circulating recordings.
4. John Kahn at Heider's: January 15 with Steve Miller; April 16 (approx) with Butterfield; August 17-18-19 with Brewer and Shipley (also Bill Vitt), as well as October 5-6-7 and 14, 1970 with Brewer & Shipley but w/o Vitt.
5. Other Garciazens making appearances in the contracts include Ron Stallings and David Crosby, though not with Jerry in these materials.
6. Martin Fierro kept pretty busy, mostly with Sir Douglas and QMS.

D. "San Francisco Rock", 1970 film contracts

In this section, I use the 1970 Bay Area Educational Television Association (i.e., KQED) "San Francisco Rock" film sessions to shed some light on San Francisco Rock, 1970 - what was played, when, etc.
1. The Concept

Ralph J. Gleason (b. - d.) was brilliant enough to see the leading edge of a wave of musical, cultural, social effervescence gathering around San Francisco from 1965 forward, turbo-boosting his own transition from newspaper jazz man to hip capitalist (Kramer 2013's formulation). He had a hand in the creation of untold countless precious artifacts including newspaper columns, radio broadcasts, interviews, records and tapes, and of course films. In 1970 KQED apparently paid him to do a five-year introspective, arranging to have the three biggest Haight-Ashbury bands filmed in "San Francisco Rock", the Airplane the first week of August, Quicksilver the first week of September, and the Dead the first week of October.

1. ca. August 3, 1970 (contract date) Family Dog on the Great Highway (film S.F. Rock): Jefferson Airplane (Balin, Dryden, Casady, Kantner, Kaukonen, Slick)
2. ca. August 31, 1970 (contract date) Sonoma State College (film – S.F. Rock, Part I): QMS (John Cipollina, Gary Duncan, David Freiberg, Greg Elmore)
3. ca. October 2, 1970 (contract date) “remote locations at Family Dog, PHR", (film – S.F. Rock): GD (Lesh [leader], Garcia, Hart, McKernan, Weir, Kreutzmann)

"San Francisco Rock" was a Ralph Gleason joint at T+5, nearly to the day. What a great idea! But, as it happens, maybe it all didn't quite work out as planned. Whatever does? So Gleason looks typically prescient in seeing the promise of marketing something at the 5 year totem, but the end results skew a little, as artifacts must.

2. The State of the Bands in/and the Broader Time Period

a. The Bands

The Jeffersons are still huge, but the peak has been passed in terms of the Airplane's live act, which I date rather precisely to 4/15/70. May brings the low swamp of Grace's "shrimp rap", the tape that turned me against live recordings of the Airplane from later in that year - I just can't get the taste of that local low off my aural palate - and by 10/4/70, or maybe it was 10/5, Marty expresses his need for a new band not just to the assembled mourners, but over howevermany watts on KPFA.

The Quick has a lot of energy in this period, but more of the kind that the the fractious Jeffersons always wallowed in, and less of the relatively --relatively!!-- interpersonally harmonious Grateful Dead scene. (I just came across a quote of Garcia saying in 1970 how well the Dead guys got along on the road - that must have been chez LIA somewhere?) There's a reason David Freiberg could jump from the Quick to the Jeffersons, besides his bad-ass bass playing, his vocal strength, song chops, and all the rest of it - he seems not to have suffered much from the burn of working with difficult, brilliant people.

The band peaked hard November 7-11, 1968 at the Fillmore West, spun the electric circle Happy Trails, and then crashed to Dino Valente's unambiguous re-entry into the band, his subsequent departure with Duncan in tow, the east coast motorcycle trip, aresulting relatively fallow first half of 1969, toodling around a little bit with Nick the Greek and then welcoming Nicky Hopkins into the fold. There is much more hot music to be played throughout the spring, but by summer 1970 Quicksilver, as it happens, is in the process of breaking apart. Nicky leaves the live act in August, Cip sort of quits after --again? 10/4/70?-- the horns come in 10/4/70 and 10/5/70 and the radio broadcast is painful to listen to. Nothing can survive the onslaught of Dino Valente --his "Long Haired Lady", which includes the line "uni-corns pran-cing, in my mind" should have earned him a lifetime ban from the commissioner-- and by 1971 they have Whodat playing the bass and would never make meaningful music again.

That said, Gleason didn't entirely miss with Quicksilver - the performance that ended up happening, being filmed, and the film eventually released is a fine one, indeed, in many respects. I say more below.

The Dead's cards showed loss, recovery and some mighty fine music, and unlike the other two bands the arrow is pointing up after 1970 - a strong buy, and go ahead and go long. The spring and fall records Workingman's Dead and American Beauty were, respectively, strong on the charts and just-released, the first a weary tune and the latter a wreath of the titular bloom. Darkness swirled around them, who took refuge in each other, sharing lives with all of their music. The last quarter of 1970 is its weakest one, by far, anchored not least by the shambolic performance that I think we have contracted here, Winterland 10/4/70.

 b. San Francisco Rock, ca. 10/4/70

Indeed, Winterland 10/4/70, the night that Janis died, the manic, brain-blasting qualities of the various broadcasts (which really were never gotten together, technically -- all of the tapes pretty much suck), the Airplane and Quicksilver falling apart at the seams, and the less well-known to me show the next night in many ways stand as an epitaph to the whole idea of getting up close and personal with "San Francisco Rock" five years along. All three "S.F. Rock" bands performed, revealing that five years will take a toll on people and the groups they comprise, living under the spotlight and fueled by all kinds of drives will bring out some really good and some, well, less so. I think it's no coincidence that the three bands contracted for "San Francisco Rock" would be playing together.
(see also LIA | cryptdev | Corry on the broadcast angle )

c. Art and Commerce

In short, I think Gleason succeeded in capturing some clear truths about "San Francisco Rock" in 1970, and I find the footage that we have to be artistically successful on a lot of levels. I don't think they worked out all that well commercially, but then again this is public television we're talking about here. The fact that Gleason gets to release this material under his own name (see just below) is interesting ...

3. The "Ralph J. Gleason Presents" DVD releases in Light of the Contracts

When I first saw the contracts, I assumed that they gave rise to film already released under the banner of "Ralph J. Gleason Presents" DVDs:

A Night at the Family Dog (EV 30122-9, 2007, IMDB)
Go Ride the Music & West Pole (Eagle Vision EV30181-9, February 2008).

I have been able to parse things a little more closely, to fine tune against the baseline of my starting assumptions. After you read this section, I want you to believe that a) the metadata around these releases contain errors, b) I can correct some of these errors using these contracts, b) none of these contracts refers to material appearing on Night at the Family Dog or West Pole; c) the Airplane and QMS contracts refer to material found on Go Ride the Music, and thus recorded in August and September 1970, respectively; and d) the 10/4/70 gig at Winterland probably constituted the Dead's  "S.F. Rock" contribution, but none of this material has never appeared in the Gleason films.

The release metadata are a little all over the place. The contracts bring clarity. Let me move from simplest to most complicated by going in the order West Pole, A Night at the Family Dog, and Go Ride the Music.

a West Pole

West Pole is the easiest to deal with. Toby Gleason says the film was made in 1968, the back cover says it aired in 1969, and the front cover says it was previously unreleased. The overall WP&GRTM release has copyrights of 1969 and 2008.

It is wonderful to see. The Airplane and Dead material on West Pole is not from discrete sessions, but colles some pastiches some rather amazing sound and image from various times and places, different kinds of sources (live and studio), and different people into primal music videos. There's great tape of legendary venues and groups such as the Ace of Cups, some street scenes from a dingy Haight, and lots of other cool stuff.

The whole thing's a hoot to watch, but it has nothing to do with  the 1970 "San Francisco Rock" sessions.

b. A Night at the Family Dog 

Filmed on 2/4/70 (update: maybe also 2/3/70) and first released in 1970, Corry has a great writeup. The metadata are very solid, two small flies in the ointment.

First, I have always supposed a "4/2/70" Airplane session  (Abbott 2007) to be spurious, probably stems from a European orthography somewhere in the script. Tape attributed this way has crossed six or seven media, and every copy I ever heard was, IIRC, the same material known to be from 2/4/70. But I note below that it is not impossible...

Second, ihor's irreplaceable The Complete Grateful Dead Discography (TCGDD) entry lists a June 28, 2005 release of the Night DVD, with otherwise identical catalog information (Eagle Rock 2030122-9), but calling it San Francisco Rock: A Night At The Family Dog. That's the sort of coincidence some of us are paid not to believe in. On my 2007 imprint of that release, that formulation ("San Francisco Rock, A Night at the Family Dog") appears as the title of Toby Gleason's brief missive. But I'd give a full title of Ralph J. Gleason Rock Classic: A Night at the Family Dog, if forced to.

I am confident out a number of decimal places that none of the material contracted during 1970 under the heading "San Francisco Rock" has anything to do with the Night at the Dog. We should be keeping these two things separate, IMO, except insofar as Toby Gleason titled an essay that way.

Overall, here, I conclude with memory rule: 2/4/70 is the Night at the Family Dog, and A Night at the Family Dog derives from only 2/4/70. (Update: except for maybe some or all of it being from 2/3/70? Heh heh.) None of this material appears to have been contracted through the papers described below.

c. Go Ride The Music

The back cover of the release says "Go Ride the Music was recorded in 1969" gives 1969 and 2008 copyrights. But 1969 is flat out incorrect. The JA and QMS tracks derive from 1970, from material contracted by KQED under the film title "San Francisco Rock".

i. Airplane

The cover reads that "the seven Airplane clips [on Ride the Music] were shot at Pacific High Recording and feature their new drummer, Joey Covington". 

The venue is a contraindication, since the contract said Family Dog. But note the wording on the Dead contract: "remote locations at Family Dog, PHR". So PHR was certainly on the script for "San Francisco Rock", and what's more --and tremendously ironically, given the story that I plan to narrate in "Jerry and the Jeffersons", parts I and II-- the Dog was busy giving birth to The Common in early August 1969, though it sure could have used the paycheck. For whatever reason, it seems very plausible to me that they contracted the Dog and ended up at PHR.

In terms of personnel, erstwhile drummer Spencer Dryden flew out of the Jeffersons' orbit by April 1970. Depending on how literally we take the word "new", this could give oxygen to the notion that there was an Airplane ssession at Family Dog on 4/2/70, despite the strikes agsinst that idea (noted above). That said, August 1970 still consists in Joey being "new" to the Airplane, I'd say, with five years (or thereabouts) already under their belts (8/13/65 is as good a starting point as any), the guy who had been in that particular seat for only three months --though around for longer-- was still "new" to a first approximation. Either way, Covington's presence as the Airplane's drummer, rather than a guy hanging out with Jack and Jorma, speaks unequivocally in favor of 1970. 

Sealing the case for 1970 for me is Jeff Swenson's liner notes. which put Garcia in the Jeffersons' studio striking Blows Against The Empire. The contracts are all over that stuff, of course, and things could not be clearer: this is summer 1970.

All in all, I am about 95% sure that work contracted for "San Francisco Rock" begat the Airplane material featured on Go Ride the Music, which therefore dates to sometime in the first third of August 1970. 

ii. Quicksilver

This QMS material completely knocks me out, Dino doing his Full Narcissist, the band tearing the shit out of things, the material very uneven. Remember this rule of thumb: "Subway" good, "Long-Haired Lady" bad. Further, any song that includes the phrase "uni-corns pran-cing in my mind" must not be. It must not be. Nicky's fingers appear a time or two, and he is clearly audible Freiburg looks like he's rocking, but he's buried in the mix, I guess that's Greg Elmore hitting the skins. It went downhill fast from here, but in September 1970 (which I'll conclude this is) these guys were at a local peak not seen since late 1968 and Happy Trails. The scenery is incredible, what looks to me like a fall day in Sonoma County, not too many people dancing out in ticklish sunshine, on a little bit of a breeze.

The "San Francisco Rock" contract fits the bill most precisely with the location  (Sonoma State College) and the season (fall). 

Personnelwise, Nicky is not on the contract, but one senses that his contractual status might have been a little bit fluid (hence the disembodied fingers on the film?). Alsoa  strike against is that, as I recalled, he had stopped gigging with the Quick in August. This certainly doesn't rule out a September 1970 QMS gig for film, which remains extremely likely given the balance of all of the evidence, but it does raise small question..

The fact that Dino Valente and Gary Duncan are in town strikes me as strongly confirmatory of 1970, since as I recall they spent all of 1969 out east riding and running around, not returning until about New Year's Eve. I'd like to consult Shelley Duncan's book again to feel more confident about that, but that's my strong sense.

All told, the balance of the evidence favors the QMS material from Go Ride the Music having been contracted as "San Francisco Rock" and performed in early September 1970.

iii. implication

Go Ride the Music comprises an early August 1970 Jefferson Airplane set from Pacific High Recorders and an early September 1970 Quicksilver Messenger set from Sonoma State College, both contracted under the planned Bay Area Educational Televation Association's planned KQED film "San Francisco Rock".

d. The Dead: All Contract, No Release

Based on all of the above, here's what I think happened with the GD session. If the Jeffersons played a different room than contracted, the Dead could have, too. And having taken that step, why not get some really live material for the film, with the people who do it best, and knock out a simulcast on KQED? In short, I now believe that the 10/2/70 contract was fulfilled by the Dead through the 10/4/70 television and radio broadcast from Winterland. Why didn't the Gleason folks use some of this footage in Go Ride the Music? My best guess is that it would have been a rights and money thing. Earlier I had entertained a few other possibilities. Maybe there really was a separate Dead session filmed during this timeframe, per the terms of the contract, which has remained hidden. This seems unlikely, to say the least. Or maybe it was never consummated (i.e., the 10/4/70 had nothing to do with the "Rock in S.F." project. Maybe the Dead bailed out after 10/4/70, Janis dead and darkness, darkness all around. But I think all of that is less likely than my preferred alternative.

Note: as far as I can tell, no video of the Dead's 10/4/70 set has been seen. Is that correct?

4. "San Francisco Rock", 1970 and San Francisco Rock, 1970

[with more time, here I would close the loop on the idea that what we get on the film is pretty much what we get in the real world. I sketched this out preliminarily above.]

Barebones session listing follows. Note that, in a pure breach of common sense, I have added a fifth line to some of the most interesting entries, to identify the songs. If I ever try to parse these into real data I'll have to remember that.

When did Jerry Garcia and Merl Saunders first play together?

Update 15 years later (summer 2025):

I had concluded it was 9/7/70.

This seems to have been incorrect.

Unheard tape suggests that was still Howard Wales. But the evidence is indirect, only a tape label that Howie Wowie's El Paso friend Martin Fierro showed up. As we know, at least as early as 5/21/71 Fierro played with the Garcia-Saunders outfit, and Martin and Merl would play on and off through the 1970s. It's possible the Howard tie is not strong enough to mean that earlier, Martin = Howard. I have a theory about Martin and Howard that I will briefly touch on in Fate Music, and I feel about 75% confident.

2025 Timeline

Corry:

Around August 1970, Cox was recording at Wally Heider Studios in San Francisco with producer Nick Gravenites, and his supporting musicians included John Kahn and Merl Saunders. Kahn took a moment to introduce Saunders to Jerry Garcia, recording in Heider's at another room. A month or two later, Saunders would join the pair at the Matrix.

8/17/70-8/20/70

Gravenites triadically closes John and Merl, connecting them from Brewer & Shipley and Danny Cox initially. AFM Local No. 6 studio session contract archives for 1970 show Brewer & Shipley at Heider's from August 17 to August 21.

I couldn't find a hint of Danny Cox until looking at San Francisco Sessions, 1971.

8/21/70: John triadically closes Merl and Jerry. Garcia is credited on the last night of sessions for pedal steel on two songs on their record Tarkio. That sequences absurdly well Corry's narrative: Gravenites employs John and Merl on some sessions, and Garcia comes in the last night. John introduces the two. Perfect.

So, yes, Jerry met Merl, as I currently understand things, on ca. 8/21/70 at Heider's

9/7/70: Martin Fierro's name appears on the tape box for 9/7/70. Do Martin's social ties point to Merl or Howard Wales in the house? I argue with about 80% confidence that the Wales-Fierro tie is vastly stronger in summer 1970 than any ties to Merl. I think that points to this being Howard. I have been researching their relationship in El Paso and it is verrrry interrrreessstingg. Jesse Jarnow's oral histories with Howard are incredible. Conjecturing further, IFJGS staff imagine that 9/7/70 was Wales's last night. Howard and Martin are tight and I mean *tight*.  IFJGS staff imagine Fierro invited or just showing up for the sendoff party. Conclusion: Wales.

For 9/14/70, the ads just say "Jerry Garcia & Friends". It is unknown whether anyone at all played keys. There is no direct or indirect evidence for Merl Saunders. Both 9/7 and 9/14 were Matrix Taped, but I have not been able to learn anything about who played what.

ca. September-start October; I believe the gap between 9/7ish and 10/12ish was partly for them to at least rehearse a little in Merl's little garage or Heider's. Saunders had been playing for pay for well over 15 years at this point.

The next advertised Garciaverse Matrix Monday night gigs were for "Jerry Garcia, Merl Sanders [sic*] and Friends", October 12-14, 1970. Even though it's Monday-Wednesday, that gig has the feel of a coming out for Merl Saunders in the Matrix Monday Night gig. Check this out - all three nights were taped. But I have not been given access to study them. At least they give us confirmation that Jerry didn't skip out after playing two shows in Paterson, NJ the night before, though of course we don't know if Jerry is on them, *doh*

Conclusion: Wales until 9/7, unknown on 9/14, Saunders commences 10/12/70. Oh yeah, and if you have any sway, please help free at least any cataloguing of these Matrix Tapes!

/fin 2025 update

For now, the basic question: when did they first play together?

In a ca. 1995-6 interview included on the DVD release of  The End of the Road: The Final Tour '95 (Monterey Video DVD 313302), Merl indicates that he went down to Golden Gate Park and played with the Grateful Dead sometime in the late 1960s. I can't offer any precision or evaluation - it's certainly possible, but is presumably utterly unknowable from this vantage point unless someone's diary or some old photographs or some other account turns up.

The Jerry Site's first listing for "Jerry Garcia and Merl Saunders" is for October 12, 1970, though if you go to the band summary for that "artist" entry it lists the first show as 12/1/70. slip_not added some Merl content (a quote about he and Jerry came to play together) on the 9/7/70 Jerry Garcia & Friends entry, but there's no obvious ex ante reason for that information to be attached to that date.

So we are in a bit of a quandary, but I have a few data points to offer.

My MO here is to examine gigs and studio sessions that might have been relevant to understanding when Jerry and Merl started together. For gigs, I am especially interested in looking at the evolution of the Monday Night Jam sessions at the Matrix, since the standard story is that Howard Wales dropped out at some point and Merl joined in. It may not have been a clean/linear break, but the data might help. For sessions, I am interested because of the Merl quote listed under 9/7/70 TJS listing linked above. There seems to have been a Heider's connection where the GD, the whole PERRO crowd (Crosby and the Jeffersons), Brewer & Shipley, and Danny Cox (the latter two of whom were under the same management) were jumping into each others' sessions to an astonishing degree.

Anyway, here are what I consider some relevant data.

• 4/20/70: Jerry Garcia and Howard Wales [double-check]; Matrix; "Scenedrome" (calendar listing), Berkeley Barb, April 17-23, 1970, p.6.
• 4/27/70: Jerry Garcia, Howard Wales, & Friends; Matrix; display ad; listed as jam session in Scenedrome; Berkeley Barb, April 24-May 1, 1970, p. 8.
• 5/18/70: Jerry Garcia and Howard Wales [double-check]; Matrix; calendar listing, Good Times v.3 n.20, 5/15/70, p. 24. I believe this is the show that was released as Side Trips, vol 1. (Aside: "Thank you, sir. May I have another?")
• 5/25/70: Howard Wales, Jerry Garcia & Friends; Matrix; Scenedrome listing in Berkeley Barb, May 22-28, 1970, p. 18. Doubtful JG was there, given GD show in the UK the night before.
• 6/1/70: Jerry Garcia and Howard Wales [double-check]; Matrix; calendar item in Good Times v.3 n.22 (5/29/70), p. 24.
• 6/7/70: this appears not to have happened.
• 6/8/70: Jerry Garcia and Howard Wales; Matrix; [source suppressed]
• 6/15/70: Jerry Garcia and Howard Wales [double-check]; Matrix; calendar item in Good Times v.3 n.24 (6/12/70), p. 24.
• 6/22/70: Jerry Garcia and Howard Wales [double-check]; Matrix; calendar item in Good Times v.3 n.25 (6/19/70), p. 23.
• 7/6/70: Jerry Garcia and Howard Wales [double-check]; Matrix; calendar item in Good Times v.3 n.27 (7/3/70), p. 17.
• 7/15/70: the first "PERRO" session at Heider's that I can document; Kantner session working on "Starship" and "Old Man" for what would become Blows Against The Empire; this and all related listings provided below show Jerry present [source suppressed]
• 7/17/70: as above, but working on "Mau Mau";
• 7/20/70: Howard Wales and Friends listed at Matrix for this Monday and the next night (Tues., 7/21/70); calendar item in Good Times v.3 n.28 (7/17/70), p. 18; no mention of Garcia.
• 7/21/70: as above.
• 7/22/70: Kantner session at Heider's ("Mau Mau"; "Together"); see 7/15/70.
• 8/6/70-9/16/70: I have the GD's American Beauty sessions at Heider's from these dates; source: McNally, LST, p. 378.
• 8/10/70: Kantner session at Heider's ("Starship"; "Old Man"); see 7/15/70.
• 8/11/70: as above ("Starship"); see 7/15/70.
• 8/21/70: Brewer & Shipley session at Heider's, for what would become Tarkio; Garcia listed ("50 States of Freedom"; "Oh Mommy"); [source suppressed]
• 8/24/70: Garcia & Wales [double-check] Monday night Matrix session; calendar item in Good Times v.3 n.33 (8/21/70), p. 21.
• 9/7/70: Jerry Garcia & Friends; Matrix; calendar item in Good Times v.3 n.35 (9/4/70), p. 16.
• 9/8/70: PERRO jams at Heider's: JG, Jorma, Jack, Kreutzmann ("Jam"); source: PERRO tapes.
• 9/14/70: Jerry Garcia & Friends; Matrix; calendar item in Good Times v.3 n.36 (9/11/70), p. 16.
• 10/12/70: "Jerry Garcia, Merl Saunders and Friends"; Matrix; based on newspaper advertisement as listed at TJS; first TJS listing for Garcia & Saunders; spurious JG listing since GD were playing in Paterson, NJ.
• 10/13/70: as above, though GD had no gig until 10/16 in Philly, and JG could well have flown home.
• 10/14/70: as above.
• 10/19/70: Jerry Garcia and Merl Saunders; Matrix; calendar item in Good Times v.3 n.41 (10/16/70), p. 20; in the past we would have discounted this, since GD was in Minneapolis on 10/18 and Washington, DC, on 10/23, but I have increasingly come around to the view that he flew home more often than I might have thought, and likely as not played a gig whenever a night was open around this time. So I buy that this could have happened.
• 10/26/70: Jerry Garcia and Merl Saunders; Matrix; calendar item in Good Times, v.3 n. 42 (10/23/70), p. 14. GD were between St. Louis (10/24) and Stony Brook (10/30), but on the logic just above I believe this could have happened.
• 11/1/70 or 11/2/70: Janis's wake. Not relevant, just wanted to keep the record straight.
• 11/2/70: I have a Jerry Garcia & Friends listing for the Harding Theater, but no source info. We have discussed this a little bit, but I am not sure where things stand.
• 11/3/70: PERRO/If I Could Only Remember My Name (IICORMN) session at Heider's ("Cowboy Movie"); based on Steve Silberman "Crosby Connection" show played on KPFA, ca. 2001.
• 11/3/70: Jerry Garcia and Merl Saunders; Matrix; note that this is a Tuesday; calendar item in Good Times v.3 n.43 (10/30/70), p. 16.
• 11/4//70: PERRO session at Heider's; no source information listed.
• 12/1/70: Jerry Garcia and Merl Saunders; Matrix; note: Tuesday; calendar item in Good Times v.3 n.47 (11/26/70), p. 20).
• 12/2/70: Jerry Garcia and Merl Saunders; Matrix; listed at TJS based on Joey Newlander newspaper research (Berkeley Barb).

Thatsalotta data, I know, but I wanted to put it out there for you all to see.

What do I infer from all of this about the titular question? The pivot looks to be right around the time of the 8/21/70 Brewer & Shipley session. (Full disclosure: in personal email, Corry played up the Brewer & Shipley connection to Danny Cox, and thence to Merl; so credit should go to Corry for helping me see the break in the series.) There's only one Wales listing a few days later, and then come the "Jerry Garcia & Friends" listings. I would guess that Merl became a "Friend" at the 9/7/70 Matrix show (otherwise why not list Wales, as they had all year?), but there is no smoking gun in these data. Merl's name doesn't appear in listings until 10/12/70, which has the drawback of being a listing known to conflict with GD performance 3000 miles away. But it certainly suggests that Merl was definitely around by this time.

I believe I spoke with Danny Cox, and he doesn't have any old paperwork regarding his sessions at Heider's. I have not tried to contact the Brewer & Shipley people, but that might be a better lead.

In sum, in answer to the question of when Jerry and Merl first played together (qua Jerry & Merl), I'll say September 7, 1970. And maybe walk back and say that slip_not may know a thing or two. ;-)