Conducting is the art of directing a musical performance, such as an orchestral or choral concert. The primary duties of the conductor are to set the tempo, ensure correct entries by various members of the ensemble, and "shape" the phrasing where appropriate. To convey their ideas and interpretation, a conductor communicates with their musicians primarily through hand gestures, typically (though not invariably) with the aid of a baton, and may use other gestures or signals, such as eye contact with relevant performers. A conductor's directions will almost invariably be supplemented or reinforced by verbal instructions or suggestions to their musicians in rehearsal prior to a performance.