Answer:

CHORUS

Answer	Crossword Clue
CHORUS	Vocal group
CHORUS	Opera participants
CHORUS	Group of singers

CHORUS	Refrain
CHORUS	Glee club, say
CHORUS	"Hallelujah" or "Anvil" follower
CHORUS	Song part
CHORUS	Commentators of old
CHORUS	Glee club
CHORUS	Line for a Broadway show?
CHORUS	Repeated song part

CHORUS	Exclaim simultaneously.
CHORUS	Part of a musical show.
CHORUS	Utter in unison.
CHORUS	Part of a song.
CHORUS	Burden of a song.
CHORUS	"A ... Line"
CHORUS	Broadway's "A ... Line"
CHORUS	Kind of line

CHORUS	Singing group
CHORUS	Speak in unison
CHORUS	Repeated part
CHORUS	Something to sing over and over
CHORUS	"How does it feel ...," in Dylan's "Like a Rolling Stone"
CHORUS	Group that's very vocal?
CHORUS	Attic drama commentators
CHORUS	Motet group

CHORUS	Feature of a classical Greek drama