Clarinet–viola–piano trio

A clarinet–viola–piano trio, often titled "Trio for Clarinet, Viola and Piano" is a work of chamber music that is scored for clarinet, viola, and piano; or is the designation for a musical ensemble of a group of three musicians playing these instruments. This combination of instruments differs from other combinations, as the viola and the clarinet share approximately the same musical range, but not the same tone quality.

Source: Wikipedia — Clarinet–viola–piano trio (CC BY-SA 4.0)