The style of blues that developed out of the migration of workers from the south to the cities of the north, and was typified by small groups of musicians performing together, was called:

Spirituals or Work Songs

Explanation:

I'm guessing you mean songs like "Crossing Jordan" or "Wading trough the Water," which would both be considered spirituals. If it were a larger group (and sung in a call-and-response pattern) they would be work songs.

answer; i believe the correct answer is in new york,in subway stations,public murals and night clubs;