As fans know, in these jams, a player shouts a tune and the group is off—melody in unison, then solos, each picking up on a phrase left by another; one starting an idea, another finishing it.

First came a catchy tune about eight oranges; then they counted off one by one while throwing up their arms in a wave.

Sports fans who are turned off by the sometimes brutal intensity of ice hockey can tune in to the gentler figure skating competition.