vocal vs work song

vocal and work song both are nouns.

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

As nouns, work song is a hyponym of vocal; that is, work song is a word with a more specific, narrower meaning than vocal:

vocal (noun)	work song (noun)
music intended to be performed by one or more singers, usually with instrumental accompaniment	a usually rhythmical song to accompany repetitious work
a short musical composition with words

vocal (adjective)	work song (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