Book rock band ... (7)
I believe the answer is:
genesis
I believe this clue is a double definition.
'book' is the first definition.
(first book of the Bible)
'rock band' is the second definition.
(I've seen this before)
(Other definitions for genesis that I've seen before include "rock group" , "rock band" , "Origin or formation of something" , "Birth, beginnings" , "the start of something" .)