Musician's soft bed (6)
I believe the answer is:
player
'musician's' is the definition.
('player' can be a synonym of 'musician')
'soft bed' is the wordplay.
'soft' becomes 'p' (musical abbreviation for 'piano'**).
'bed' becomes 'layer' (I've seen this before).
'p'+'layer'='PLAYER'
(Other definitions for player that I've seen before include "Sports participant" , "Participant in competitive game" , "Actor; sportsman" , "Professional musician - team sportsperson" , "Participant in soccer match or other game" .)