doo-wop vs gospel singing

doo-wop and gospel singing both are nouns.

Word	Noun	Adjective	Verb	Adverb
doo-wop	Yes	No	No	No
gospel singing	Yes	No	No	No

As nouns, gospel singing is a hypernym of doo-wop; that is, gospel singing is a word with a broader meaning than doo-wop:

doo-wop: a genre (usually a cappella) of Black vocal-harmony music of the 1950s that evolved in New York City from gospel singing; characterized by close four-part harmonies; the name derived from some of the nonsense syllables sung by the backup
gospel singing: folk music consisting of a genre of a cappella music originating with Black slaves in the United States and featuring call and response; influential on the development of other genres of popular music (especially soul)

Other hypernyms of doo-wop include gospel.

doo-wop (noun)	gospel singing (noun)
a genre (usually a cappella) of Black vocal-harmony music of the 1950s that evolved in New York City from gospel singing; characterized by close four-part harmonies; the name derived from some of the nonsense syllables sung by the backup	folk music consisting of a genre of a cappella music originating with Black slaves in the United States and featuring call and response; influential on the development of other genres of popular music (especially soul)