He had a lifetime of rock and roll! (8)
I believe the answer is:
sisyphus
'he had a lifetime of rock and roll' is the definition.
The definition suggests a singular noun which matches the answer.
'he' is the wordplay.
I cannot really understand how this works, but
'he' could be 'si' and 'si' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for sisyphus that I've seen before include "Legendary Greek king doomed to forever roll a boulder uphill" , "Plead case" , "Man faced with an uphill task" , "He had an endless job" , "King of Ephyra, condemned to push a boulder uphill for ever" .)