If you’ve been doing music a while, you’ll find that you have somewhere about your house, boxes of cassette tapes and quarter-inch reels full of jam sessions, recorded gigs, experiments, “demo” recordings, band practices and other bits and pieces of your music-related outpourings.
Generally speaking, most people consider these too good to throw away, and not good enough to let anyone else hear them. Either the performances were off, the sound quality was awful, the singer was dire on that session, it was a slightly different line-up of the band, you were still learning your instrument, you were just mucking around… or whatever.
Digitise it. Digitise it all.