Underground versus mainstream

[Brokenjaw]

I could be wrong, but I think the term "underground" refers to obscure music that is not played on radio or MTV and people have to actively seek out. Everyone knows the Doors, Joplin, Hendrix, etc. I wasn't around during that era so maybe they started off underground and when everyone realized how good they are they became popular. But at this point, I would consider those groups mainstream (especially the Beatles).

UMM I was going for underground as in DEAD. You know 6 feet under.