A big band orchestra is a mid-sized musical performance group that plays big band jazz. Generally, these groups have between 15 and 30 members playing rhythm, string, and wind instruments. This type of group usually plays a type of music called big band swing. Some big band orchestras play old-time jazz standards, while others play original swing-style music. While the types and numbers of instruments in a big band orchestra can vary slightly, there are some basic instruments most people expect to see in this type of group.
Standard instruments in the wind instrument section of a big band orchestra include saxophones, trumpets, and trombones. There are usually multiple instrumentalists playing each type of wind instrument. Sometimes, a non-standard type of instrument like a flute, french horn, or tuba may join the wind section. Some jazz ensembles also have singers.
The basic rhythm section in a big band orchestra includes an electric guitar and bass guitar or acoustic bass instrument alongside drums and a piano or keyboard. Some jazz groups may also have a mallet instrument like a marimba or vibraphone. A big band orchestra always has a drummer playing a drum kit and usually includes a second drummer playing auxiliary percussion like congas, wood blocks, and chimes.
There are ideally five saxophones in a big band saxophone section. Generally, the section includes two alto saxophones, two tenor saxophones, and one baritone saxophone. Saxophone players often play more than one type of saxophone. Alto or tenor saxophonists may switch to the soprano saxophone for solos in some songs. It is important to have at least one strong saxophone soloist on alto and tenor, since these instruments have frequent solos in big band jazz pieces.
Generally, brass instruments in a big band orchestra include four or five trombones and three or four trumpets. One of the trombones is often a bass trombone, a type of trombone designed to reach a lower range than the standard trombone. Usually, the trumpet section in a big band group includes at least one trumpet player capable of loudly projecting the high notes on a trumpet.
This type of performance group differs from jazz combos because the music in a big band orchestra relies much more upon written music than combo music, which is largely improvisational. Big band orchestra music does often contain improvisational solos, but improvisation plays much less a part of the overall performance than in a jazz combo performance.