Velocitron band

The Velocitron band is a group of neutral Transformers from the planet of Velocitron in the Cybertron portion of the Unicron Trilogy.

What kind of Transformers society evolves a need for a trombone player?

The Velocitron band is a group of no fewer than fifteen Transformers who appear to perform at important racing events on the planet Velocitron.

Led by a drum major, the band consists of five drummers, four cymbalists, a trombone player, two musicians on unidentified brass instruments, and at least four others.

One of the cymbalists and a drummer seem to be female.

Fiction

Animated continuity

Cybertron cartoon

The Velocitron band was hired (or required) to perform at the opening ceremonies for the final Planet Cup race. Their brass section could be heard playing at the time. Champion

Their further activities (and any additional performances) are unknown.

From Teletraan I: The Transformers Wiki, a Wikia wiki.