aleatory music vs chance music

aleatory music and chance music both are nouns.

Word	Noun	Adjective	Verb	Adverb
aleatory music	Yes	No	No	No
chance music	Yes	No	No	No

As nouns, aleatory music and chance music are synonyms defined as:

aleatory music and chance music: 20th-century music in which chance or indeterminate elements are left for the performer to realize.

Other synonyms of aleatory music include aleatoric music.

aleatory music (noun)	chance music (noun)
20th-century music in which chance or indeterminate elements are left for the performer to realize.	20th-century music in which chance or indeterminate elements are left for the performer to realize.