Clue: Cats love playing a bit of music (7)
Answer: TOCCATA
Explanation: Definition: a 

***(cat cat o)** where CAT CAT = "cats" in the clue, and O = "love" in tennis
 
This is clever, but I'm not sure it's fair, It requires a second step, so doesn't that make it similar to an indirect anagram? Maybe "two cats" might have been better.