Cassettes can last 30 years plus, but if they've been in someone's car deck and have been stopped, started, rewinded and fast forwarded many times, the tape is likely to be stretched. I do like the analogue sound of tape, especially on headphones, its pretty damn loud compared to MP3. But you listen to a lot of 20's, 30's and 40s jazz on cassette issued in the 70s and 80s and its in desperate need of a decent remastering which the golden era of CD reissues brought in.
I have quite a few of the BBC cassettes that issued 1920s and 30s jazz in stereo. Surprisingly, it worked!
Was that Robert Parker? I had the Johnny Dodds and loved the sound.