Charge to recruit tenor for festival (4)
I believe the answer is:
fete
'for festival' is the definition.
(synonyms)
'charge to recruit tenor' is the wordplay.
'charge' becomes 'fee' (fee is a kind of charge).
'to recruit' indicates putting letters inside (in the sense of bringing in).
'tenor' becomes 't'.
'fee' placed around 't' is 'FETE'.
(Other definitions for fete that I've seen before include "Entertain regally" , "Marilyn Monroe's real first name' constellation" , "lavish entertainment" , "Outdoor entertainment and sale, often for charity" , "Lavishly entertain; charity function" .)