The person who sings in a band or group — the singer, as opposed to the people playing guitar, drums, or keyboard. The word exists mostly because a band needs a name for that job. On a poster or an album sleeve you will see "vocalist: ..." listed next to "drummer" and "bassist". In everyday talk people just say "singer"; "vocalist" sounds slightly more technical, the word of someone who thinks about music as a set of roles. It is used for popular music — rock, jazz, pop — not usually for opera or classical singers, who are called singers or by their voice type. You will also meet "lead vocalist" (the main singer) and "backing vocalist" (the ones singing behind), and a band can have several. Music teachers and audition notices like the word because it names the skill, not the fame.