Charts restoring Rotten's band (6,9)
I believe the answer is:
string orchestra
'band' is the definition.
(type of musical group)
'charts restoring rotten's' is the wordplay.
'rotten's' indicates an anagram.
'charts'+'restoring'='chartsrestoring'
'chartsrestoring' with letters rearranged gives 'STRING ORCHESTRA'.
(Other definitions for string orchestra that I've seen before include "Players" , "group" .)