Chap spent age making music (6)
I believe the answer is:
reggae
'music' is the definition.
(I know that reggae is a type of popular music)
'chap spent age' is the wordplay.
'chap' becomes 'reg' ().
'spent' indicates anagramming the letters.
'age' is an anagram of 'gae'.
'reg'+'gae'='REGGAE'
'making' is the link.
(Other definitions for reggae that I've seen before include "Jamaican musical style" , "Jamaican music style" , "West Indian music with strong subsidiary beat" , "Music style from Jamaica" , "Type of music developed in Jamaica in the 1960s" .)