The trombone is a staple in almost all forms of big band music usually as part of an entire section in most jazz and funk ensembles. Although the most common version of the instrument, the tenor trombone, is pitched in Bb it is not a transposing instrument and is typically written in C with some rare exceptions.
The most common type of the instrument in jazz, funk and contemporary music. While most often part of a horn section the tenor trombone can also be found on its own in small horn combos or even used as a lead/melody instrument in multiple genres.
Usually part of a trombone section the bass trombone is similar in range and construction to the tenor but has a darker, weightier sound that is especially effective in the lower register. Sounds great when pared with a tenor or group of tenors to fill out the low end and add some extra heaviness to the sound; there are some examples in jazz of it being used as a lead instrument but it is most commonly used as part of a section.