Musician of 50s, friend to prickly bush (5,5)
I believe the answer is:
buddy holly
'musician' is the definition.
(I know that Buddy Holly is a rock star)
'friend to prickly bush' is the wordplay.
'friend' becomes 'buddy' (buddy is a kind of friend).
'to' is a charade indicator (letters next to each other).
'prickly bush' becomes 'holly' (holly is a type of bush. I am not sure about the 'prickly' bit.).
'buddy'+'holly'='BUDDY HOLLY'
'of 50s' acts as a link.
This may not be correct. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Another definition for buddy holly that I've seen is " singer".)