Eminent performer in some art form! (7)
I believe the answer is:
maestro
'eminent performer' is the definition.
'maestro' can be an answer for 'performer' (I have seen 'Outstanding performer ' mean 'maestro' so perhaps 'performer' could also mean 'maestro'). I'm not certain of the 'eminent' bit.
'some art form' is the wordplay.
'form' is an anagram indicator (another form of the letters).
'some'+'art'='someart'
'someart' with letters rearranged gives 'MAESTRO'.
'in' acts as a link.
Can you help me to learn more?
(Other definitions for maestro that I've seen before include "Eminent conductor or composer" , "Some art (anag.)" , "musical genius" , "Top music man" , "Eminent musician" .)