arranger vs musician

arranger and musician both are nouns.

Word	Noun	Adjective	Verb	Adverb
arranger	Yes	No	No	No
musician	Yes	No	No	No

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

arranger: a musician who adapts a composition for particular voices or instruments or for another style of performance
musician: artist who composes or conducts music as a profession

arranger (noun)	musician (noun)
a person who brings order and organization to an enterprise	artist who composes or conducts music as a profession
a musician who adapts a composition for particular voices or instruments or for another style of performance	someone who plays a music as a profession