Matrix
History
The Matrix was a small club at 3138 Fillmore Street in the Marina, and its origin is unusually tidy for a scene that mostly grew by accident: the singer Marty Balin opened it on August 13, 1965 essentially as a home room for the band he was assembling, Jefferson Airplane, who were its de facto house act in those first months. Where the Fillmore and the Avalon were big rooms built for the light-show dance concert, the Matrix was a club — a converted pizza parlor, low-ceilinged and intimate, seating a couple hundred — and it stayed open, on and off, into 1972, long after the ballroom boom peaked. That intimacy made it a recording room as much as a stage: much of the early live tape of the San Francisco bands (the Airplane, Quicksilver, the Great Society, and the Blues Project's September 1966 residency among them) was cut at the Matrix, which is why it turns up in the historical record out of proportion to its size. It is best understood as the scene's laboratory and green room — where bands auditioned, tried out material, and were first captured on tape — rather than as one of its grand halls.
Its Place in the Scene
The incubator club: Jefferson Airplane's first home room and the scene's principal small-club recording venue, distinct from the light-show ballrooms.