Jazz combo

A jazz band (jazz ensemble or jazz combo) is a musical ensemble that plays jazz music. Jazz bands vary in the quantity of its members and the style of jazz that they play but it is common to find a jazz band made up of a rhythm section and a horn section.

The size of a jazz band is closely related to the style of jazz they play as well as the type of venues in which they play. Smaller jazz bands, also known as combos, are common in night clubs and other small venues and will be made up of three to seven musicians; whereas big bands are found in dance halls and other larger venues.

Jazz bands can vary in size from a big band, to a smaller trio or quartet. The term jazz trio can refer to a three piece band with a pianist, double bass player and a drummer. Some bands use vocalists, while others are purely instrumental groups. Jazz bands usually have a bandleader. In a big band setting, there is usually more than one player for a type of instrument.

Jazz bands and their composition have changed many times throughout the years just as the music itself changes with each performers personal interpretation and improvisation which is one of the greatest appeals of going to see a jazz band.

Small jazz bands of three to four musicians are often referred to as combos and can be found in small night club venues. In modern jazz, an acoustic bass player is almost always present in a small band, complemented by any other combination of instruments.

It's common for musicians in a combo to perform their music from memory. The improvisational nature of these performances make every show unique.

In jazz, there are several types of trios. One type of jazz trio is formed with a piano player, a bass player and a drummer. Another type of jazz trio that became popular in the 1950s and 1960s is the organ trio, which is composed of a Hammond organ player, a drummer, and a third instrumentalist (either a saxophone player or an electric jazz guitarist). In organ trios, the Hammond organ player performs the bass line on the organ bass pedals while simultaneously playing chords or lead lines on the keyboard manuals. Other types of trios include the "drummer-less" trio, which consists of a piano player, a double bassist, and a horn (saxophone or trumpet) or guitar player; and the jazz trio with a horn player (saxophone or trumpet), double bass player, and a drummer. In the latter type of trio, the lack of a chordal instrument means that the horn player and the bassist have to imply the changing harmonies with their improvised lines.

...
Wikipedia