Rock band's creation (7)
I believe the answer is:
genesis
This clue is a double definition.
'rock band's' is the first definition.
(I've seen this before)
'creation' is the second definition.
(I've seen this before)
(Other definitions for genesis that I've seen before include "name of group" , "Band; book" , "Bible's first book" , "Beginning the holy book" , "First book of the Bible" .)