The Matrix, at 3138 Fillmore Street in San Francisco, was the original hippie hangout, even before their were hippies. Founded by Marty Balin and his father, the club provided a place to play for the newly-formed Jefferson Airplane on August 13, 1965. Numerous other groups either debuted or made their San Francisco debut there, such as Big Brother and The Holding Company (on January 10, 1966). The Matrix was also a clubhouse and hangout for what few underground pothead musicians were around at the time. As the scene expanded, and the Fillmore and Avalon became major venues, the Matrix became as a hangout as much as a club. Although The Matrix only served beer and pizza, hippies were very much not welcome at many establishments, and in any case it took a while for rock music to become the dominant form of music in San Francisco nightclubs, so the Matrix was the best small place in the City for rock.
Fortunately for rock fans, Matrix co-owner Peter Abrams recorded just about every performance at The Matrix, which is why so many tapes from the club circulate. Due to the expense of reel-to-reel tape, Abrams could not preserve every single performance, but he made an effort to preserve the best ones, and fans of many groups have benefited. Jerry Garcia played the Matrix in many odd incarnations from 1968 to 1971, and many interesting tapes circulate. One of the most interesting tapes that has circulated over the years is dated Wednesday, February 19, 1969. Garcia plays banjo with the East Bay bluegrass group High Country, his only recorded bluegrass performance between 1964 and 1973.
When I initially wrote this post, I focused on the fact that High Country were not scheduled for February 19, 1969 at The Matrix (Jorma Kaukonen and Jack Casady with Weird Herald were booked). It has since been pointed out to me that the Dead definitely played the Fillmore West on February 19, 1969, so the date has to be incorrect. However, this wouldn't be the first time that Matrix tapes represented the correct week but not necessarily the exact date. I think this is a result of the owners selecting the best performances and then taping over the others, with a less-than-ideal result for marked boxes. Since Jerry Garcia was booked for February 24 and 26 (with Phil Lesh and Bill Kreutzmann in "Mickey Hart and The Hartbeats") I have to presume now that High Country was playing an opening set for one of these gigs.
Although Garcia is plainly audible between songs (discussing what numbers to play, and so on), the tape circulated for many years with constantly incorrect performer information. Many people including myself thought that it featured Peter Rowan on vocals and David Grisman or Frank Wakefield on mandolin. In fact, this was just bluegrass naivete: the group performs standards that every bluegrass player would know, and on the Bill Monroe numbers singer Butch Waller evokes Monroe, just as Rowan did. Waller was the mandolinist as well, as Grisman was in a rock band on the East Coast at the time (Earth Opera, with Rowan), and Wakefield would not meet Garcia for several more years.
Eventually someone played the tape for David Nelson, who explained who really was playing. High Country was a bluegrass band that had formed in late 1968 in Berkeley. Leaders Butch Waller (mandolin) and Rich Wilber (bass, guitar) teamed with Rick Shubb (banjo) and his girlfriend Markie Sanders (guitar). Shubb was a Palo Alto roommate and friend of Garcia's, and an artist who had done some posters for the Carousel Ballroom. Waller was from the East Bay and had been in an early 60s group called the Westport Singers with Herb Pedersen, and, in the mid-60s, The Pine Valley Boys with David Nelson, so Waller too went way back with the South Bay bluegrass crowd.
Rick Shubb and his girlfriend moved on, but Waller and Wilber kept the band together with various members for several months, including old pal David Nelson, band-less after The New Delhi River Band had broken up, and fellow former Pine Valley Boy Richard Greene, when he wasn't playing with Sea Train. On this one occasion, at least, Jerry Garcia joined in with Waller, Wilber and David Nelson to play as a bluegrass quartet, fortunately preserved on tape. Bluegrass groups played the Matrix rarely, if at all, but that is only because the hippies who played there weren't playing much bluegrass at the time. Its unclear whether or how much Garcia played with High Country beyond this gig, but in any case the band found new members and continues to thrive today.
(note: since I have revised my view of the date, I have moved my ruminations about Jorma Kaukonen and Billy Dean Andrus elsewhere)