Singer otherwise 'Mr Silent' (8)
I believe the answer is:
minstrel
'singer' is the definition.
(minstrel is a kind of singer)
'otherwise mr silent' is the wordplay.
'otherwise' indicates anagramming the letters.
'mr'+'silent'='mrsilent'
'mrsilent' is an anagram of 'MINSTREL'.
(Other definitions for minstrel that I've seen before include "Medieval wandering musician" , "Jongleur" , "one entertains" , "Old song 'The ... boy to the wars has gone'" , "Strolling player" .)