String trio String trio A string trio is a group of three string instruments or a piece written for such a group. The term is generally used with reference to works of chamber music from the Classical period to the present. From at least the 19th century on, the term "string trio" with otherwise unspecified instrumentation normally refers to the combination violin, viola and cello (cf "string quartet", "piano trio" etc.). This is how the term is used by major catalogs, including IMSLP. The earliest string-trio form, found in the early Classical period, consisted of two violins and a cello, a grouping
String quintet a double bass, and Mozart's famous "Eine kleine Nachtmusik" may be performed with this instrumentation (the double bass being optional). Alternative additions include clarinet or piano (see clarinet quintet, piano quintet); and other closely related chamber music genres include the string quartet (much more common), the string trio, and the string sextet. A more unusual form of string quintet is the "violin quintet" composed of 3 violins, a viola and a cello (thus a string quartet with an additional violin). The term "string quintet" may refer to a group of five players that performs such works. The ensemble was standard