Song from Callas maybe minutes away (4)
I believe the answer is:
aria
'song' is the definition.
(aria is a kind of song)
'callas maybe minutes away' is the wordplay.
'callas maybe' becomes 'maria' (Maria Callas is an example).
'minutes' becomes 'm'.
'away' indicates named letters should be taken away.
'maria' with 'm' taken away is 'ARIA'.
'from' acts as a link.
(Other definitions for aria that I've seen before include "Air in an opera" , "Operatic air" , "Repeated strain" , "Operatic solo performance" , "Opera solo" .)