Virtuoso changed pin again (8)
I believe the answer is:
paganini
'virtuoso' is the definition.
Both the answer and definition are singular nouns.
Perhaps there's an association between them I don't understand?
'changed pin again' is the wordplay.
'changed' is an anagram indicator.
'pin'+'again'='pinagain'
'pinagain' anagrammed gives 'PAGANINI'.
Can you help me to learn more?
(Other definitions for paganini that I've seen before include "Violinist and composer" , "Old bower" , "Nineteenth century violin virtuoso" , "was often on the fiddle" , "Famous violin virtuoso" .)