Combo's leader plays new love song (7)
I believe the answer is:
calypso
'song' is the definition.
(thesaurus)
'combo's leader plays new love' is the wordplay.
'leader' indicates taking the first letters.
'new' is an anagram indicator.
'love' becomes 'o' (In tennis, 'love' means 'zero').
The initial letter of 'combos' is 'c'.
'plays' anagrammed gives 'alyps'.
'c'+'alyps'+'o'='CALYPSO'
(Other definitions for calypso that I've seen before include "Topical West Indian song - orchid - sea nymph" , "Keeper of the Ithacan king" , "West Indian song with variable rhythm and improvised words" , "ad-libbed, topical ballad" , "who detained Odysseus?" .)