singer vs instrumentalist

singer and instrumentalist both are nouns.

Word	Noun	Adjective	Verb	Adverb
singer	Yes	No	No	No
instrumentalist	Yes	No	No	No

As nouns, instrumentalist is a hypernym of singer; that is, instrumentalist is a word with a broader meaning than singer:

Other hypernyms of singer include musician, player.

singer (noun)	instrumentalist (noun)
a person who sings	someone who plays a music as a profession