What instruments are in a jazz band?

A jazz band is built on a rhythm section, which is the bass, the drums and a piano or a guitar. Between them they keep the time and play the chords. On top go the instruments that play the tune, usually a saxophone, a trumpet, a trombone or a singer, and in the smallest bands the piano or guitar plays the tune itself.

Which of those instruments you’ll hear depends on the size of the band. A jazz band can be as small as two musicians or as large as a big band, and each size in between has a name and a usual lineup.

The first four instruments here make up the rhythm section. The saxophone, the trumpet and the trombone are what jazz musicians call the horns.

• Piano. Plays the chords behind whoever has the melody, and takes solos of its own.
• Guitar. Does the same job as the piano, so a small band often has one or the other. In jazz it’s most often an electric guitar played with a clean, warm tone.
• Upright bass. Also called the double bass, it’s the big bass that stands on the floor, plucked with the fingers. On a swing tune it plays one note on every beat, which musicians call a walking bass line, and the rest of the band keeps time with it. Some bands swap it for an electric bass guitar.
• Drums. A drum kit, with the drummer keeping time mostly on the ride cymbal, the large cymbal to one side of the kit. It’s played with sticks, or with wire brushes for a softer sound.
• Saxophone. It comes in four common sizes, soprano, alto, tenor and baritone, from high to low. Alto and tenor are the two you’ll hear most in a small band.
• Trumpet. The high, bright brass horn. With a mute in the bell it’s softer and its tone changes.
• Trombone. The low brass horn with a slide. In a larger band it fills out the harmony under the trumpets and saxophones.
• The singer. Sings the melody and the words, and steps aside while the band plays its solos.

Less often you’ll see a clarinet, a flute or a vibraphone, which looks like a xylophone with metal bars and is played with mallets.

A small jazz band is called a combo, and each size takes its name from how many musicians are in it.

• A duo is two musicians. Common jazz duos are guitar and upright bass, piano and bass, or a singer with a piano or a guitar. Without a drummer the bass keeps the pulse, and a duo is the quietest jazz band you can book.
• A trio is three, most often a piano or a guitar with bass and drums, and the drums give it a steady beat under the melody. Its other lineups, and the trio that suits a private event, are set out in what a jazz trio is.
• A quartet is four, a rhythm section plus a saxophone, a trumpet or a singer out front. With someone else on the melody, the piano or guitar is free to play the chords behind it. The Dave Brubeck Quartet, the band on Take Five, was piano, alto saxophone, bass and drums.
• A quintet is five, and the usual lineup is a trumpet and a tenor saxophone in front of piano, bass and drums. The two horns play the melody together, either on the same notes or in harmony. Miles Davis’s quintets in the 1950s and 60s had that lineup.
• Sextets, septets and octets have six, seven and eight musicians, and each added musician is usually another horn, such as a trombone or a second saxophone.

A big band is a jazz band of ten or more musicians, and the standard lineup today is seventeen, arranged in four sections. The saxophone section is five players, usually two altos, two tenors and a baritone. Then come four trumpets and four trombones, and a rhythm section of piano, guitar, bass and drums. Many big bands also have a singer.

A big band plays from written arrangements. The sections trade phrases back and forth and come together for the loudest passages, and the solos go in the spaces the arranger leaves for them. It’s the sound of the swing era of the 1930s and 40s, when bands like Duke Ellington’s and Count Basie’s played for dancing.

A jazz band plays mostly standards. A jazz standard is a song so widely played that jazz musicians all know it, which means a band can play it together without rehearsing it first. Many come from the Broadway shows and Hollywood films of the 1920s to the 1950s, the songs called the Great American Songbook, and others were written by jazz musicians themselves. All the Things You Are is from a 1939 Broadway musical, and Take the A Train was written for Duke Ellington’s orchestra. A band usually plays the melody once through, takes turns improvising solos over the same chords, and plays the melody again to end the song.

The jazz we book runs from a single guitarist to a quartet, playing the standards at every size. What to book depends on how many guests you’re expecting and whether there’ll be dancing.

The jazz duo and trio is upright bass and guitar at a volume guests talk across, and it covers a cocktail hour, a dinner, or both on one booking. The duo suits a dinner of twenty at one table or eighty at ten. For a larger crowd or a longer night the trio adds drums, played with brushes so the level stays where the duo had it. Add a horn or a singer and it’s the quartet, which plays the swing and soul end of the standards for a dance floor.

Changes Jazz Trio is a Denver trio of guitar, fretless bass and drums that plays the standards with a modern edge, and its page says who the three musicians are. A saxophone joins it as a quartet when a gala or a client dinner wants a featured set.

At a wedding, one jazz booking can grow through the day, from a solo guitarist or the duo at the ceremony to the quartet for the dancing, and the jazz band for a wedding page sizes each part of it. The corporate jazz band page does the same for a company evening, with the band going silent for the speeches and the awards. What the market charges for each size, with its sources, is set out in what a jazz band costs in Denver.