Works in shop, with no quiet period (5)
I believe the answer is:
opera
'works' is the definition.
(I've seen this before)
'shop with no quiet period' is the wordplay.
'with no' indicates named letters should be taken away.
'quiet' becomes 'sh'.
'period' becomes 'era' (era is a kind of period).
'shop' with 'sh' removed is 'op'.
'op'+'era'='OPERA'
'in' acts as a link.
(Other definitions for opera that I've seen before include "E.g. Falstaff, Fidelio" , "Tosca, for example" , "Eg, The Magic Flute" , "Eg, La forza del destino" , ""Rigoletto", for example" .)