Wide selection of actors give a sound performance (9)
I believe the answer is:
broadcast
'give a sound performance' is the definition.
'broadcast' can be an answer for 'give' (thesaurus). I am not sure about the 'a sound performance' bit.
'wide selection of actors' is the wordplay.
'wide' becomes 'broad' (synonyms).
'selection of actors' becomes 'cast' (I can't explain this - if you can you should believe this answer much more).
'broad'+'cast'='BROADCAST'
Can you help me to learn more?
(Other definitions for broadcast that I've seen before include "Transmit by radio or TV" , "Sow" , "Transmission" , "Show" , "Send out by radio or television" .)