Inclination to write song (8)
I believe the answer is:
penchant
'inclination' is the definition.
(a penchant for something is an inclination for it)
'write song' is the wordplay.
'write' becomes 'pen' (synonyms).
'song' becomes 'chant' (song sung by a crowd).
'pen'+'chant'='PENCHANT'
'to' is the link.
(Other definitions for penchant that I've seen before include "Leaning towards or liking for" , "Predilection, preference" , "Willingness" , "Partiality" , "Strong liking, inclination" .)