Some Hungarian song (4)
I believe the answer is:
aria
'song' is the definition.
(piece of music in an opera)
'some hungarian' is the wordplay.
'some' indicates a hidden word (some parts of the word are used).
'ARIA' is hidden within 'hungarian'.
(Other definitions for aria that I've seen before include "Summertime perhaps" , "Song from an opera (4)" , "Vocal solo in a cantata etc" , "Operatic solo performance" , "Song, one from 'West Side Story' needing no introduction" .)