crooner vs vocaliser

crooner and vocaliser both are nouns.

Word	Noun	Adjective	Verb	Adverb
crooner	Yes	No	No	No
vocaliser	Yes	No	No	No

As nouns, vocaliser is a hypernym of crooner; that is, vocaliser is a word with a broader meaning than crooner:

Other hypernyms of crooner include singer, vocalist, vocalizer.

crooner (noun)	vocaliser (noun)
a singer of popular ballads	a person who sings
	an organism that can utter vocal sounds