music vs whistling

music and whistling both are nouns.

Word	Noun	Adjective	Verb	Adverb
music	Yes	No	No	No
whistling	Yes	No	No	No

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

music (noun)	whistling (noun)
musical activity (singing or whistling etc.)	the act of whistling a tune
punishment for one's actions	the act of signalling (e.g., summoning) by whistling or blowing a whistle
any agreeable (pleasing and harmonious) sounds	the sound made by something moving rapidly or by steam coming out of a small aperture
(music) the sounds produced by singers or musical instruments (or reproductions of such sounds)
an artistic form of auditory communication incorporating instrumental or vocal tones in a structured and continuous manner