Later on towards the end of 1962 [Pigpen] got a part-time job at Swain's Music Store in Palo Alto, and it was there more than anywhere else that the Grateful Dead seed began to grow. ... Now Swain's Music Store, where Pigpen was working, was run by a guy named Troy Weidenheimer who had ideas about forming his own rock'n'roll band. He of course knew Pigpen, Pigpen knew Garcia, Garcia knew Kreutzmann, and so … a short-lived band called the Zodiacs was formed. Troy played lead guitar, Pigpen was on harp. They used a wide selection of drummers but most of the time it was Bill Kreutzmann, and Garcia would sometimes join in on bass guitar when he wasn't involved with his own bluegrass groups.
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