There are 3 major types of trombones in use today. Let’s explore them a bit.
Tenor Trombone
The most common type of trombone is the tenor trombone. The tenor trombone is the trombone you’ll see in the hands of the players in the trombone section of a band. It has a sound that is deep and full.

In its simplest form it is called a straight trombone, meaning “without F-attachment”.
The tenor trombone is pitched in Bb and sheet music should be notated in bass clef. Advanced players should also be able to read tenor clef, but bass clef is by far the most commonly used.
Tenor trombones often come with a trigger, or F-attachment, which add additional tubing to the horn and changes the tuning from Bb to F.
Bass Trombone
The bass trombone has a larger bore than the tenor and usually has an F-attachment (valve) and a secondary valve to extend the low-end even more. The second valve lowers the tuning to Gb, or (less common), to G.
The bass trombone is pitched in Bb and has the same length of tubing as the tenor trombone. It has a lager bore, a lager bell, and a larger mouthpiece though.
Alto Trombone
The alto trombone is pitched in Eb and is less common than tenor and bass trombones. There is orchestral music scored for alto trombone, but professional players comfortable playing the alto are few. It is common to use alto trombones in music schools for smaller kids as they are unable to reach the outer positions of a tenor trombone before a certain age.

Other kinds of trombones
There are a whole range of trombones that are rarely used. Some of them are:
- Soprano
- Sopranino
- Superbone
- Valve trombone
- Sackbut
- Cimbasso
- Contrabass