The music of love to a Manx cat? (4)
I believe the answer is:
opus
'the music' is the definition.
(opus is a kind of music)
'love to a manx cat?' is the wordplay.
'love' becomes 'o' (love means zero in tennis).
'to a manx' means to remove the last letter (the word has no 'tail', like a Manx cat).
'cat?' becomes 'puss' (puss is a kind of cat).
'puss' with its final letter taken away is 'pus'.
'o'+'pus'='OPUS'
'of' acts as a link.
(Other definitions for opus that I've seen before include "Musical piece" , "Showing creative skill" , "A Latin work" , "Composer's work" , "Artistic work" .)