Individual pieces sought but not named (4)
I believe the answer is:
soli
'individual pieces' is the definition.
'soli' can be an answer for 'pieces' (solo is a kind of piece). I'm not sure about the 'individual' bit.
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for soli that I've seen before include "Parts for one performer" , "one-man performances" , "individual performances" .)