Rich store performed by singer (9)
I believe the answer is:
chorister
'singer' is the definition.
(singer in a choir)
'rich store performed' is the wordplay.
'performed' indicates anagramming the letters.
'rich'+'store'='richstore'
'richstore' is an anagram of 'CHORISTER'.
'by' acts as a link.
(Other definitions for chorister that I've seen before include "Boy in church" , "Boy singing" , "Choir member" , "Boy singer" , "Choirboy or girl" .)