A group is a collection of players.

In most scores, there is a single group, for example a choir, an orchestra, or a band. In some works for large forces, there may be multiple groups, for example, in Britten's War Requiem, which has three distinct groups, or Walton's Belshazzar's Feast which requires two separate off-stage brass groups. These make it necessary to be able to assign players to these groups for the purposes of, among other things, properly bracketing and labeling their staves in the conductor's score.