There's a trumpeter playing on "Roadrunner", the last song of set I of the show known as "August 15, 1974, Great American Music Hall" through a tape made by Bob Menke and/or Louis Falanga. Listen to the first five minutes. Guy (presumably) is pretty good.
I will be doing a post on this show, about which I have some questions, and will be doing another roundup post on "Garcia's Unidentified Guests" (or at least the trumpet playing!). For now, just NB another trumpeter, ca. August 1974.