Maazel’s stardom regularly revealed a great conductor (7)
I believe the answer is:
maestro
'a great conductor' is the definition.
(I've seen this before)
'maazel's stardom regularly revealed' is the wordplay.
'regularly revealed' indicates alternate letters.
'maazels'+'stardom'='maazelsstardom'
The alternating letters of 'maazelsstardom' are 'MAESTRO'.
(Other definitions for maestro that I've seen before include "Great figure" , "Eminent musician" , "Distinguished musician - most are (anag)" , "Means of payment" , "Virtuoso" .)