yodeller vs singer

yodeller and singer both are nouns.

Word	Noun	Adjective	Verb	Adverb
yodeller	Yes	No	No	No
singer	Yes	No	No	No

As nouns, singer is a hypernym of yodeller; that is, singer is a word with a broader meaning than yodeller:

yodeller: a singer who changes register rapidly (popular in Swiss folk songs)
singer: a person who sings

Other hypernyms of yodeller include vocaliser, vocalist, vocalizer.

yodeller (noun)	singer (noun)
a singer who changes register rapidly (popular in Swiss folk songs)	a person who sings