art vs musicianship

art and musicianship both are nouns.

Word	Noun	Adjective	Verb	Adverb
art	Yes	No	No	No
musicianship	Yes	No	No	No

As nouns, musicianship is a hyponym of art; that is, musicianship is a word with a more specific, narrower meaning than art:

art: a superior skill that you can learn by study and practice and observation
musicianship: artistry in performing music

art (noun)	musicianship (noun)
the creation of beautiful or significant things	artistry in performing music
the products of human creativity; works of art collectively
a superior skill that you can learn by study and practice and observation
photographs or other visual representations in a printed publication