A style of performance where a soloist alternates with a choir is called: O A. polyphony.
O B. direct psalmody.
C. antiphonal psalmody.
O D. responsorial psalmody.

D. responsorial psalmody

The answer is D. Responsorial Psalmody.

Explanation:

In responsorial singing, the soloist (or choir) sings a series of verses, each one followed by a response from the choir (or congregation).

Responsorial psalmody is a method of performance (especially in Gregorian chant) in which a solo voices alternates with the chorus. The solo passage is known as a "verse" and the choral answer is the "response". The singing therefore involves the contrast between two dissimilar bodies of sound. Responsorial singing, also known as call-and-response, is found in the folk music of many cultures.

12-bar blues chorus = a a b