musical octave vs octave

musical octave and octave both are nouns.

Word	Noun	Adjective	Verb	Adverb
musical octave	Yes	No	No	No
octave	Yes	No	No	No

As nouns, musical octave and octave are synonyms defined as:

musical octave (noun)	octave (noun)
a musical interval of eight tones	a musical interval of eight tones
	a rhythmic group of eight lines of verse
	a feast day and the seven days following it