accompanist vs instrumentalist

accompanist and instrumentalist both are nouns.

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

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

accompanist: a person who provides musical accompaniment (usually on a piano)
instrumentalist: someone who plays a music as a profession

Other hypernyms of accompanist include musician, player.

accompanist (noun)	instrumentalist (noun)
a person who provides musical accompaniment (usually on a piano)	someone who plays a music as a profession