Greenlanders..had a rather jolly system for resolving disputes. The contestants competed by singing satirical songs and making hurtful remarks about each other while playing a shallow drum, the issue being decided on the strength of each side's performance
(From next week's Radio Times* previewing a BBC radio 4 programme by Clive Anderson on Greenland Law.

*(Like the TV Guide in USA)

RtS
(the shallow drum bit sounds scary!)