
The term backline is used in
popular music
Popular music is music with wide appeal that is typically distributed to large audiences through the music industry. These forms and styles can be enjoyed and performed by people with little or no musical training.Popular Music. (2015). ''Fun ...
and
sound reinforcement system
A sound reinforcement system is the combination of microphones, signal processors, amplifiers, and loudspeakers in Loudspeaker enclosure, enclosures all controlled by a mixing console that makes live or pre-recorded sounds louder and may also ...
contexts to refer to electronic audio
amplification equipment and
speaker enclosure
A loudspeaker enclosure or loudspeaker cabinet is an enclosure (often rectangular box-shaped) in which speaker drivers (e.g., woofers and tweeters) and associated electronic hardware, such as Audio crossover, crossover circuits and, in some ca ...
s that are placed behind the band or the
rhythm section
A rhythm section is a group of musicians within a music ensemble or band that provides the underlying rhythm, harmony and pulse of the accompaniment, providing a rhythmic and harmonic reference and "beat" for the rest of the band.
The rhythm ...
on
stage, including
amplifiers and speaker cabinets for
guitars,
bass guitars and
keyboards. Such equipment is often rented or leased by the band or their management, or provided by the venue. Speakers placed at the front of the stage facing the performers are also known as
monitor speakers or "foldback". The main speakers facing the audience are sometimes referred to as "
front of house speakers".
History
In
rock music
Rock is a Music genre, genre of popular music that originated in the United States as "rock and roll" in the late 1940s and early 1950s, developing into a range of styles from the mid-1960s, primarily in the United States and the United Kingdo ...
's early days,
PA systems were not very loud or powerful, so 1960s rock bands typically used the PA system just for the vocals, even if they were playing at a large venue. As a result, the
rhythm section
A rhythm section is a group of musicians within a music ensemble or band that provides the underlying rhythm, harmony and pulse of the accompaniment, providing a rhythmic and harmonic reference and "beat" for the rest of the band.
The rhythm ...
musicians playing
electric guitar
An electric guitar is a guitar that requires external electric Guitar amplifier, sound amplification in order to be heard at typical performance volumes, unlike a standard acoustic guitar. It uses one or more pickup (music technology), pickups ...
,
electric bass
The bass guitar (), also known as the electric bass guitar, electric bass, or simply the bass, is the lowest-pitched member of the guitar family. It is similar in appearance and construction to an electric but with a longer neck and scale leng ...
and
keyboards were expected to produce enough volume to fill the venue using their own
instrument amplifier
An instrument amplifier is an electronic amplifier that converts the often barely audible or purely electronic signal of a musical instrument into a larger electronic signal to feed to a loudspeaker. An instrument amplifier is used with music ...
s. To achieve venue-filling sound with their instruments, bands from the 1960s typically used large, powerful guitar "stacks" and big
speaker enclosure
A loudspeaker enclosure or loudspeaker cabinet is an enclosure (often rectangular box-shaped) in which speaker drivers (e.g., woofers and tweeters) and associated electronic hardware, such as Audio crossover, crossover circuits and, in some ca ...
s. A standard cabinet used by bassists during this era was the heavy 8x10 cabinet, which contains eight ten-inch speakers. Guitarists used one or two 4x12 cabinets, referred to, respectively, as a half stack or (full) stack.
During the 1960s, the PA speakers and the band's amplification were all set in a line, which conceptually grouped PA and instrument amplification together. This changed over the 1970s and 1980s, as PA systems became powerful enough to amplify all of the band's instruments and the vocals. During this era, the backline gear was set behind the PA speakers to create the modern audio stage set-up. Modern monitoring techniques, in which
monitor speakers pointing at the performers are placed on the stage, as well as the concepts of frontline and backline, developed during this era.
Backline equipment can be rented for concert tours. Many travelling musicians prefer not to transport their own gear across borders and continents for fear of damage or customs hassles. In some countries, all electronic and electric gear needs documentation and certification by an electrical expert before it can be brought into the country. Another issue is that some bands may travel to a country or continent which uses a different type of
AC mains power and differently-shaped electric plugs.
Festivals and venues provide backline gear because it speeds up the process of changing bands on a stage, because the gear does not have to be moved on and off the stage and then
soundcheck
A soundcheck is the preparation that takes place before a concert, speech, or similar performance to adjust the sound on the venue's sound reinforcement or public address system. The performer and the audio engineers run through a small po ...
ed again. Having professional backline gear means that the sound engineers do not have to deal with modest-quality amplifiers.

An emerging group on small club tours will not usually have the negotiating leverage to request specific brands and models of backline gear. However, top bands may have very specific backline requirements, including a list of amplifiers and instruments, and also the brand names and model numbers.
Roles
Backline
guitar technicians, audio technicians and stage crew set up and put away the backline equipment.
In places where the backline is left in place indefinitely (e.g., in a nightclub's mainstage or a TV variety show studio), the gear may simply be powered down when not in use. In
music festival
A music festival is a festival, community event with music, performances of singing and instrument playing that is often presented with a theme such as musical genre (e.g., rock music, rock, blues, folk music, folk, jazz, classical music), nation ...
s with outdoor temporary stages, the backline equipment may have to be transported to a locked, climate-controlled storage area at the end of each day, to protect it from theft, vandalism and the weather.
Backline techs who travel with touring acts may also be called
roadies, although the road crew's role typically is limited to transporting and positioning the instruments and gear. Maintenance and repair of instruments and gear is a specialized task handled by guitar, keyboard and drum technicians.
References
{{reflist
Stage terminology
Rhythm section
Popular music