Question

what describes the performing forces of hildegards alleluia? a soloist sings it all. a choir sings it all, with a smaller group of voices on the verse. this music alternates between soloist and choir (singing the same line, or, in monophony).

Explanation:

Hildegard's "Alleluia" often features alternation between soloist and choir singing the same line in a monophonic texture. This is a common performance - style characteristic of her works.

Answer:

This music alternates between soloist and choir (singing the same line, or, in monophony).