guitar player vs musician

guitar player and musician both are nouns.

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

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

Other hypernyms of guitar player include instrumentalist, player.

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