two-note call vs song

two-note call and song both are nouns.

Word	Noun	Adjective	Verb	Adverb
two-note call	Yes	No	No	No
song	Yes	No	No	No

As nouns, song is a hypernym of two-note call; that is, song is a word with a broader meaning than two-note call:

Other hypernyms of two-note call include birdcall, birdsong, call.

two-note call (noun)	song (noun)
a birdcall having two notes	the act of singing
	a short musical composition with words
	the characteristic sound produced by a bird
	a distinctive or characteristic sound
	a very small sum