A musical ensemble, also known as a music group, musical group, or a band is a group of people who perform instrumental and/or vocal music, with the ensemble typically known by a distinct name. Some music ensembles consist solely of instrumentalists, such as the jazz quartet or the orchestra. Other music ensembles consist solely of singers, such as choirs and doo-wop groups. In both popular music and classical music, there are ensembles in which both instrumentalists and singers perform, such as the rock band or the Baroque chamber group for basso continuo (harpsichord and cello) and one or more singers. In classical music, trios or quartets either blend the sounds of musical instrument families (such as piano, strings, and wind instruments) or group instruments from the same instrument family, such as string ensembles (e.g., string quartet) or wind ensembles (e.g., wind quintet). Some ensembles blend the sounds of a variety of instrument families, such as the orchestra, which uses a string section, brass instruments, woodwinds, and percussion instruments, or the concert band, which uses brass, woodwinds, and percussion. In jazz ensembles or combos, the instruments typically include wind instruments (one or more saxophones, trumpets, etc.), one or two chordal "comping" instruments (electric guitar, acoustic guitar, piano, or Hammond organ), a bass instrument (bass guitar or double bass), and a drummer or percussionist. Jazz ensembles may be solely instrumental, or they may consist of a group of instruments accompanying one or more singers. In rock and pop ensembles, usually called rock bands or pop bands, there are usually guitars and keyboards (piano, electric piano, Hammond organ, synthesizer, etc.), one or more singers, and a rhythm section made up of a bass guitar and drum kit.