I'm reasonably sure I was responsible for putting this into the world of CD-R's.
Many years ago, Stephen Barstow had sent me a bunch of Man live stuff on cassette. I then recorded them onto CD-R with the occasional slight edit to fit (nothing too drastic - fading audience applause early and suchlike). There were also some shorter things that were fitted onto one CD-R, mostly because they could.
My memory tells me this gig was one of those. I was pretty active in trading circles in those days (I blame Neil Young) so the stuff started to be shared. And once that process starts, you can''t really stop it!!
I subsequently shared lists with Pete Gifford and we filled out each other's gaps (NB - this is not a euphemism

).