Musician from orchestra burps occasionally in sonata's traditional opening (6)
I believe the answer is:
oboist
'musician' is the definition.
(oboist is a kind of musician)
'orchestra burps occasionally in sonata's traditional opening' is the wordplay.
'opening' indicates taking the first letters.
The initial letters of 'orchestra burps occasionally in sonatas traditional' is 'OBOIST'.
'from' is the link.
(Other definitions for oboist that I've seen before include "Wind player" , "orchestra member" , "Musician who plays woodwind of treble pitch" , "Instrumentalist" , "Player of woodwind instrument of treble pitch" .)