As in a Maria Callas recording? (4)
I believe the answer is:
aria
'maria callas recording?' is the definition.
I can't tell whether this defines the answer.
'as in a' is the wordplay.
'as in' becomes 'ari' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'ari'+'a'='ARIA'
Can you help me to learn more?
(Other definitions for aria that I've seen before include "Musical performance" , "Song, one from 'West Side Story' needing no introduction" , "Operatic solo, duet, etc" , "Air in an opera" , "Song for solo voice from an oratorio, cantata etc" .)