A salesperson with nothing turning up for musical drama (5)
I believe the answer is:
opera
'musical drama' is the definition.
(an opera is a drama performed in music)
'a salesperson with nothing turning up' is the wordplay.
'salesperson' becomes 'rep' (sales rep).
'with' means one lot of letters go next to another.
'nothing' becomes 'O' (looks like zero - 0).
'turning up' says the letters should be written backwards.
'a'+'rep'+'o'='arepo'
'arepo' reversed gives 'OPERA'.
'for' acts as a link.
(Other definitions for opera that I've seen before include "Eg, Rigoletto" , "Macbeth for one" , "Musical in which all the words are sung" , "Music and drama production" , "Musical works" .)