School of Rock admitting primarily undiscovered talent (5)
I believe the answer is:
tutor
'school' is the definition.
(I've seen this before)
'rock admitting primarily undiscovered talent' is the wordplay.
'rock' becomes 'tor' (tor is a kind of rock**).
'admitting' is an insertion indicator.
'primarily' says to take the initial letters.
The initial letters of 'undiscovered talent' is 'ut'.
'tor' going around 'ut' is 'TUTOR'.
'of' acts as a link.
(Other definitions for tutor that I've seen before include "Master" , "Give individual instruction" , "School" , "Private educator" , "Private or university teacher" .)