Backing vocalists sing with the lead vocalist in a band.
 In some pop and hip hop groups and in musical theater, they may be required to perform dance routines while singing through headset microphones
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

