musical organization vs musical group

musical organization and musical group both are nouns.

Word	Noun	Adjective	Verb	Adverb
musical organization	Yes	No	No	No
musical group	Yes	No	No	No

As nouns, musical organization and musical group are synonyms defined as:

musical organization and musical group: an organization of musicians who perform together

Other synonyms of musical organization include musical organisation.

musical organization (noun)	musical group (noun)
an organization of musicians who perform together	an organization of musicians who perform together