premise: Backing vocalists are performers.
hypothesis: Backing vocalist . In many rock and metal bands ( e.g. , the power trio ) , the musicians doing backup vocals also play instruments , such as guitar , electric bass , drums , or keyboards . In Latin or Afro-Cuban groups , backup singers may play percussion instruments or shakers while singing . In some pop and hip-hop groups and in musical theater , the backup singers may be required to perform elaborately choreographed dance routines while they sing through headset microphones . In pop and country songs , backup vocalists may perform vocal harmony parts to support the lead vocalist . Karthik (singer) . Karthik started his professional career as a backing vocalist and has since been working as a playback singer .