In brief, a string quartet is accompanied with a piano. A string quintet has two violins, a viola and a cello.

A piano quintet would typically comprise a string quartet (2 violins, viola and cello) and, of course, a piano. The string quartet is the standard medium for chamber music, and the addition of piano adds a dimension of contrasting tonal colors as well as a solid harmonic framework to complement the strings.

An ensemble, a choir, a group, or a specific name based on the number (a quartet is with 4 people (also known as a Barbershop Quartet), a quintet with 5, septet with 7 etc.).

The different types of musical ensembles are trio, quartet, quintet, sextet, septet, and octet.

First Piano Quartet was created in 1941.