religious song vs vocal

religious song and vocal both are nouns.

Word	Noun	Adjective	Verb	Adverb
religious song	Yes	No	No	No
vocal	Yes	Yes	No	No

As nouns, vocal is a hypernym of religious song; that is, vocal is a word with a broader meaning than religious song:

Other hypernyms of religious song include church music, religious music, song.

religious song (noun)	vocal (noun)
religious music for singing	music intended to be performed by one or more singers, usually with instrumental accompaniment
	a short musical composition with words

religious song (adjective)	vocal (adjective)
	having or using the power to produce speech or sound
	relating to or designed for or using the singing voice
	given to expressing yourself freely or insistently
	full of the sound of voices