An awful chore, dressing the star dancer and musicians (9)
I believe the answer is:
orchestra
'musicians' is the definition.
(I've seen this before)
'an awful chore dressing the star' is the wordplay.
'an awful' is an anagram indicator.
'dressing' indicates an anagram.
'chore' is an anagram of 'orche'.
'star' anagrammed gives 'stra'.
'orche'+'stra'='ORCHESTRA'
'dancer and' acts as a link.
This may not be right. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for orchestra that I've seen before include "Group of musicians found on cart-horse" , "Sort of stall" , "Musical ensemble" , "Large group of players" , "players in pit" .)