Quintet

A quintet is a formation containing exactly five members. It is commonly associated with musical groups, such as a string quintet, or a group of five singers, but can be applied to any situation where five similar or related objects are considered a single unit.

In classical music, any additional instrument (such as a piano, clarinet, oboe, etc. joined to a the usual string quartet (two violins, a viola, and a cello), is called a "piano quintet", "clarinet quintet", etc., as is a piece of music scored for such a group.

The Opera Carmen contains an particularly engaging quintet (not always performed), by singers playing some of the smugglers.

Five humans sharing the same gestational period are called quintuplets and are usually all born within a short period of time.