Encouragement to listen to Beethoven's fourth (5)
I believe the answer is:
heart
'encouragement' is the definition.
(as in taking heart from something)
'listen to beethoven's fourth' is the wordplay.
'listen to' becomes 'hear' (to hear something is to listen to it).
'beethoven's fourth' becomes 't' (4th letter of 'beethoven').
'hear'+'t'='HEART'
'to' is the link.
(Other definitions for heart that I've seen before include "Vital organ - centre - courage" , "Playing card - pity" , "Decorated (cake)" , "Central part" , "It's in the chest" .)