Cavalry trombone

The valve trombone is a brass instrument in the trombone family that has a set of valves to vary the pitch instead of (or in addition to) a slide. Although it has been built in sizes from alto to contrabass, it is the tenor valve trombone pitched in B♭ an octave lower than the trumpet which has seen the most widespread use. The most common models have three piston valves. They are found in jazz and popular music, as well as marching bands in Europe, where they are often built with rotary valves and were widely used in orchestras in the 19th century.