Offstage musicians and singers are performers who play instruments and/or sing backstage, out of sight of the audience, during a live popular music concert at which the main band is visible playing and singing onstage. The sound from the offstage musicians or singers is captured by a microphone or from the output of their instrument, and this signal is mixed in with the singing and playing of the onstage performers using an audio console and a sound reinforcement system. Offstage backup singers are also used in some Broadway musicals, as have offstage instrumentalists, in cases where an onstage actor needs to appear to play an instrument.
The offstage musicians and singers are typically located beside the stage, behind the speaker stacks, backstage, under the stage (for raised stages), or, for music festivals held out of doors, in a tent near the backstage area.
Terminology
Offstage performers may be called an "offstage touring guitarist", "offstage touring keyboard player", "offstage guitarist", "offstage keyboardist", "offstage backup singer" or "offstage harmony singer". In music theatre, singers may be called "pit singers" or "offstage voices". Slang terms are also used, such as "ghost singer".
Roles
Some offstage performers are hired solely to play one or more instruments (e.g., synthesizer, rhythm guitar, percussion). Some offstage performers are hired solely to sing backup vocals. Some offstage performers are hired to play an instrument and sing backup or harmony vocals at the same time. Offstage musicians can be hired for one-off concerts, but they are generally hired for entire tours. Some offstage musicians or singers work with the same band for many years.
In Broadway musicals, some of the offstage singers may have a secondary role as understudy to one of the onstage singers; the understudy (also called the "cover", "standby" or "alternate") sings the part of the onstage actor in front of the audience, in costume, in the event that the main singer becomes ill.
Some offstage performers have another profession or role that they perform in addition. Iron Maiden offstage keyboardist Michael Kenney's other role is as the bassist's bass tech.
Acknowledgement
Some offstage performers are asked to sign a nondisclosure agreement which forbids them from doing interviews regarding their offstage performance work for a certain group. Sharon Osbourne states that Ozzy Osbourne's offstage singers and musicians are acknowledged in concert programs and, for concerts that are recorded, in the recording credits. Alan Fitzgerald was the offstage keyboard player for Bruce Springsteen's Devils & Dust Tour. In the final two shows of the tour, Springsteen invited Fitzgerald up on stage, introduced him, and played with him. When Alan Fitzgerald played off-stage keyboards for Van Halen, he was credited as Eddie Van Halen's "keyboard technician", a euphemism which acknowledged Fitzgerald's role as a keyboard player without admitting Fitzgerald was an offstage performer. Terry Lawless is credited in some sources as a keyboard technician and keyboard programmer for the band he works for.
Approaches
The instrumental playing by offstage performers is captured by a microphone for acoustic instruments such as acoustic guitar; by mic in front of the guitar amplifier and/or a DI unit output for an electric instrument such as electric bass, by mic for electric guitar (in front of the guitar amp) and Hammond organ with a Leslie speaker, or for an electronic instrument such as a synthesizer, by getting the signal from the instrument's output. Singing is captured by a microphone.
In all cases, the signal from the instruments and/or microphones are routed to the multicore cable (often nicknamed the "snake") and then plugged into the mixing board. Once the offstage musicians and singers' signals are plugged into the mixing board, the audio engineer can blend their sounds in with the playing and singing of the onstage musicians (which is also captured by microphones and/or signal cables). The mixed output is then routed to the PA system or sound reinforcement system, the combination of power amplifiers and speaker enclosures which outputs the concert sounds for the audience.