A bit late to the party, couple of random thoughts ...
Benny Goodman - what about his work with Bartok, will that be remembered ?
The Grateful Dead (aka the Dreadful Great) - "bit over-rated" and "why were they not generally heard of ?". When they were good, they were very very good, but when they were bad they were horrid. They had some really good songs (ie, I liked them) and a lot of bad ones (ie, I didn't) - some of them would stand remembering, and could be played by other people, would work as songs in their own right, but songs are 2-a-penny, there's a lot of competition. If they deserve to be remembered, it would be for their long instrumental episodes, which are *chewy* and tend to take them out of the "popular" category. They take a lot of listening to. Generally, it was a band that needed patience and a fairly high level of interest to get much out of.
Recording. Paper is not the only artificial memory any longer. This changes things.