A(n) is an operatic number involving three or more leading singers.

Ensemble

Explanation:

The musical group is usually not a big group. Various ensembles are formed by different music groups from different genres. There are many groups. For example, a jazz ensemble, a quartet or a trio.

The ensembles are organized, with leading singers and parts such as soprano, alto, tenor, and bass. In men's singing groups, there is also a mixture of tenor and base known as the baraton.