A boy band is loosely defined as a vocal group consisting of young male singers, usually in their teenage years or in their twenties at the time of formation. Generally, boy bands perform love songs marketed towards girls and young women. Many boy bands dance as well as sing, usually giving highly choreographed performances. South Korean boy bands usually also have designated rappers.

A musical ensemble, also known as a music group or musical group, 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 and one or more singers. In classical music, trios or quartets either blend the sounds of musical instrument families or group instruments from the same instrument family, such as string ensembles or wind ensembles. 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.