Didn't have time to fix it. I counted 8 myself but didn't use a program to do it.

No worries.

This has 10 colours. Please fix this before the challenge deadline.

aaaaaaah kkkkk ... bullseye = zakk wylde!! damn, shoulda known that w/o the clue... shame on me :D 

edit: band is black label society of course...
edit2: forgot to comment on the piece itself ^^ ... really like it pixelwise and (even more) musicwise :D 4/5

Spinal Tap's amps go to 11   ;o)  Point to eldiabolito.

Second clue is the 'bullseye' in the background.

spinal tap because of the volume knob... i don't know... there's so many bands playing marshall amps... well, i'm pretty sure i got one right :D 

Thanks dpixel.

Great guess, and two awesome bands...but zero points. (it's not a clock, and that's my Marshall stack ;o)  )

Nice background...very musical.  My guesses would be Pink Floyd because of the clock and The Who for the Marshall-looking stack.