Show to repeat changes (8)
I believe the answer is:
operetta
'show' is the definition.
(I've seen this before)
'to repeat changes' is the wordplay.
'changes' indicates an anagram.
'to'+'repeat'='torepeat'
'torepeat' is an anagram of 'OPERETTA'.
(Other definitions for operetta that I've seen before include "piece of music?" , "Sung entertainment" , "Light musical theatre" , "Make light work" , "Showboat or The Gondoliers, say" .)