The upper middle panel of the Ghent Altarpiece shows:

Doo Wop groups

A. Merged R & B and classical music B. Started on street corners C. Began in the American South D. Usually played guitars

A distinctive feature of this composition is the fact that it?

a) is entirely in duple meter b) is entirely in triple meter c) moves from duple to triple time and then back to duple d) moves from triple to duple time and then back to triple