cornetist vs player

cornetist and player both are nouns.

Word	Noun	Adjective	Verb	Adverb
cornetist	Yes	No	No	No
player	Yes	No	No	No

As nouns, player is a hypernym of cornetist; that is, player is a word with a broader meaning than cornetist:

Other hypernyms of cornetist include instrumentalist, musician.

cornetist (noun)	player (noun)
a musician who plays the trumpet or cornet	a theatrical performer
	a person who participates in or is skilled at some game
	someone who plays a music as a profession
	a person who pursues a number of different social and sexual partners simultaneously
	someone who takes part in an activity