A composer we rang about (6)
I believe the answer is:
wagner
'a composer' is the definition.
(Richard Wagner)
'we rang about' is the wordplay.
'about' indicates anagramming the letters.
'we'+'rang'='werang'
'werang' is an anagram of 'WAGNER'.
(Other definitions for wagner that I've seen before include "Noted German" , "German cycle-maker" , "Composer of ''The Flying Dutchman'' etc" , "Composer honoured in Bayreuth" , "German composer of The Ring Cycle" .)