Bit too off topic for the "chantwell" thread.

Morris-ey (22 Mar 10 - 11:41AM):

"Call-and-response goes back to ancient Greek theatre: it is, as a form, very old."

CELEUS'MA (κέλευσμα). The chaunt or cry given out by the cockswain (hortator, pausarius, κελευστής) to the rowers of Greek and Roman vessels, in order to aid them in keeping the stroke, and encourage them at their work. (Mart. Ep. iii. 67. Rutil. I. 370.) The chaunt was sometimes taken up, and sung in chorus by the rowers, and sometimes played upon musical instruments. Auson. in Div. Verr. 17.

Rich, Anthony, A Dictionary of Roman and Greek Antiquities with Nearly 200 Engravings on Wood From Ancient Originals, (London: Longman, Green, & Co., 1884, p.140)