[timdev2]

At some point, probably in the 70s, Frank Zappa began obsessively multi-tracking nearly-all performances (at significant cost back then). This led to a bunch of interesting output, including things like compositions based on an improvised guitar solo, separated from it's original backing, and placed in a completely different harmonic context. Also, lots of straight-up live compilations (with some overdubs), chiefly the You Can't Do That On Stage Any More (YCDTOSA) series, which is a six volume set of double-CDs.

For most people, back in those days, getting a sufficiently high-quality recording of a live show was prohibitively expensive.

Like Phish, Zappa was very much a cottage industry, unmolested by mainstream music industry stuff after the very early days.