cassette only releases: bonus tracks 80s/90s

No idea about the cassette question but a couple of my favorite soundtracks from the 80s are "Mike's Murder" and "Until The End Of The World."
Come to think of it I actually have a copy of "Mike's Murder" on cassette. If you were my neighbor I'd give it to you as I no longer have a cassette player. Some day I'll need to decide what to do with all those cassettes.

The bonus track scenario plays out on 12 inch single format as well.I always felt the British were the kings of releasing items that have the "one extra odd live" song to milk any extra cash out of fanatics (that's me in this case).A hit would have 7 inch,12 inch,CD single,and cassete versions in the 90s each ever so slightly different.As far as 90s S'Tracks "Straight To Hell","Walker" and "Blue Velvet".

The Grateful Dead released "My Brother Esau" as the flip side to the cassette single of "Touch of Grey" on a grey cassette. It was also the flip side of the 45, but was later replaced. It was not on the album (In the Dark).

All time best cassette artist: Daniel Johnston.