Musician playing clarinet with cop (4,7)

I believe the answer is:

eric clapton

'musician' is the definition.
(rock musician)

'playing clarinet with cop' is the wordplay.
'playing' is an anagram indicator.
'with' means one lot of letters go next to another.
'clarinet' put after 'cop' is 'copclarinet'.
'copclarinet' anagrammed gives 'ERIC CLAPTON'.

I've seen this clue in The Guardian.

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