Pasta essential to player, a violinist (7)
I believe the answer is:
ravioli
'pasta' is the definition.
(I know that ravioli is a type of pasta)
'essential to player a violinist' is the wordplay.
'essential to' says the answer is hidden in the clue (letters in the inside or essence of the clue).
'RAVIOLI' is hidden within 'player a violinist'.
(Other definitions for ravioli that I've seen before include "Small, filled cases of dough" , "(Meat, cheese, etc filled) pasta cases" , "food parcels" , "Filled pasta squares" , "Small stuffed pasta" .)