A backing vocalist is a singer who provides vocal harmony with the lead vocalist or other backing vocalists. A backing vocalist may also sing alone as a lead-in to the main vocalist's entry or to sing a counter-melody. Backing vocalists are used in a broad range of popular music, traditional music, and world music styles. Solo artists may employ professional backing vocalists in studio recording sessions as well as during concerts. In many rock and metal bands (e.g., the power trio), the musicians doing backing vocals also play instruments, such as guitar, electric bass or keyboards. In Latin or Afro-Cuban groups, backing singers may play percussion instruments or shakers while singing. In some pop and hip hop groups and in musical theater, they may be required to perform dance routines while singing through headset microphones. Styles of background vocals vary according to the type of song and genre of music. In pop and country songs, backing vocalists may sing harmony to support the lead vocalist. In hardcore punk or rockabilly, other band members who play instruments may sing or shout backing vocals during the chorus (refrain) section of the songs. Terminology Alternative terms for backing vocalists include backing singer, backing vocals, additional vocals or, particularly in the United States and Canada, backup singer, background singer, or harmony. Examples While some bands use performers whose sole on-stage role is backing vocals, backing singers commonly have other roles. Two notable examples of band members who sang back-up are The Beach Boys and The Beatles. The Beach Boys were well known for their close vocal harmonies, occasionally with all five members singing at once such as "In My Room" and "Surfer Girl". The Beatles were also known for their close style of vocal harmonies – all of them sang both lead and backing vocals at some point, especially John Lennon and Paul McCartney, who frequently supported each other with harmonies, often with fellow Beatle George Harrison joining in. Ringo Starr, while not as prominent as a singer due to his distinctive voice, sings backing vocals in such tracks as "The Continuing Story of Bungalow Bill" and "Carry That Weight". Examples of three-part harmonies by Lennon, McCartney and Harrison include "Nowhere Man", "Because", "Day Tripper", and "This Boy". The members of Crosby, Stills, Nash & Young and Bee Gees each wrote songs, sang backup or lead vocals, and played various instruments in their performances