What existing materials could be precedence for The Great Wheel of Eurovision?

Eurovision has been around since 1956 and DnD just a little bit less.

What existing materials could be used as precedence for an EPIC annual contest between bards, where each of the Outer planes in the Great Wheel Cosmology puts forward one performing representative (a talented bard), an Over The Top contest occurs, and delegates from all planes vote on the winner?

Part of what this would entail a contest between bards. Are there existing modules or campaign references that have a contest between bards, including ways to adjudicate besides "roll a skill check"?

The GM has access to both the Pathfinder reference "The Great Beyond" and the 3.5e "Manual of the Planes." The Great Wheel Cosmology would be preferred over the Pathfinder planar treatment: what existing "outer plane" materials in either system would be of use here?

Asking for a friend, whose Players though it would be fun to create a party that is a band (all the PCs are musicians, not all are bards) and the GM wants to punish them. This question also partially inspired by the recent movie Eurovision Song Contest: the story of Fire Saga.

This group primarily plays Pathfinder 1e but other material could be tweaked/twisted/ squeezed into shape.