The second smaller bell has a brighter tone, similar to a baritone horn or valve trombone.

By age 12 he was playing valve trombone.

John Sanders - valve trombone (tracks 1, 3 & 5)

He first took up music at a very young age and was playing the valve trombone by age 11.

Instead of a slide, the valve trombone has three valves like those on a trumpet.

Some trombones have valves instead of a slide (see valve trombone).

Yet, as he attested, Ellington never once mentioned that he would like to hear him play the valve trombone.

He studied composition formally during this period, as well as taking up the valve trombone.

At age 12, he started lessons on valve trombone and the larger baritone horn.

Harper played valve trombone in the all-city band, but soon after switched to piano.