koto player vs musician

koto player and musician both are nouns.

Word	Noun	Adjective	Verb	Adverb
koto player	Yes	No	No	No
musician	Yes	No	No	No

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

Other hypernyms of koto player include instrumentalist, player.

koto player (noun)	musician (noun)
a musician who plays the koto	artist who composes or conducts music as a profession
	someone who plays a music as a profession