Musical performers half taken aback (4)
I believe the answer is:
cats
'musical' is the definition.
(Andrew Lloyd Webber musical)
'performers half taken aback' is the wordplay.
'performers' becomes 'cast' (I've seen this before).
'half' means to take half the letters.
'taken aback' becomes 'ts' (I can't explain this - if you can you should believe this answer much more).
'cast' with half the letters taken is 'ca'.
'ca'+'ts'='CATS'
Can you help me to learn more?
(Other definitions for cats that I've seen before include "Spectacular Llyod Webber feline musical" , "Show" , "Popular musical" , "Famous feline Lloyd Webber musical" , "Domestic pets" .)