Band plays as host entertains (4)
I believe the answer is:
sash
'band' is the definition.
(a band of material)
'plays as host entertains' is the wordplay.
'entertains' indicates a hidden word (the answer is welcomed or entertained by the clue).
'SASH' can be found hidden inside 'plays as host'.
(Other definitions for sash that I've seen before include "Popular band in Northern Ireland" , "Strip of cloth - type of window" , "Brown bread for waist or shoulder" , "Girdle" , "Strip of cloth worn round the waist" .)