Play live with American tenor (4)
I believe the answer is:
beat
'play' is the definition.
(as in playing or beating a percussion instrument)
'live with american tenor' is the wordplay.
'live' becomes 'be' (synonyms).
'with' means one lot of letters go next to another.
'american' becomes 'a' (common abbreviation - e.g. in organisation names).
'tenor' becomes 't'.
'be'+'a'+'t'='BEAT'
(Other definitions for beat that I've seen before include "buffet" , "Policeman's route; strike" , "Strike; pulsate" , "Pound - defeat" , "See 22" .)