OK, so, bop over to this gallery in my LJ pics and see how many musicians you can name. I've got answers for all but 2 of them, so I hope you know those two. ;)
By the way, no, I don't know where they came from originally, if you do, I'd love to know...and I'd love you to not cheat by checking there for answers. Some of them are obvious (both amusingly and painfully), some of them are obscure. At least one of them is someone I've listened to for years...and had never actually seen, so I had a hard time getting it (and once I saw them, it was so obvious that it HURT).
No more screening, but feel free to check the pix first if you want to play.