In classical music, a piano quintet is a work of chamber music written for piano and four other instruments, most commonly (since 1842) a string quartet (i.e., two violins, viola, and cello). The term also refers to the group of musicians that plays a piano quintet. The genre flourished during the nineteenth century. Until the middle of the nineteenth century, most piano quintets were scored for piano, violin, viola, cello, and double bass. Following the success of Robert Schumann's Piano Quintet in E♭ major, Op. 44 in 1842, which paired the piano with a string quartet, composers increasingly adopted Schumann's instrumentation, and it was this form of the piano quintet that dominated during the second half of the nineteenth century and into the twentieth century. Among the best known and most frequently performed piano quintets, aside from Schumann's, are Schubert's Trout quintet and the piano quintets of Johannes Brahms, César Franck, Antonín Dvořák and Dmitri Shostakovich.

A string quintet is a musical composition for five string players. As an extension to the string quartet (two violins, a viola, and a cello), a string quintet includes a fifth string instrument, usually a second viola (a so-called "viola quintet") or a second cello (a "cello quintet"), or occasionally a double bass. Notable examples of classic "viola quintets", in four movement form include those of Wolfgang Amadeus Mozart. Other examples were written by composers including Johannes Brahms and Felix Mendelssohn. A famous "cello quintet" is Franz Schubert's Quintet in C major. Antonín Dvořák's Quintet Op. 77 uses a double bass, and Mozart's famous Eine kleine Nachtmusik may be performed with this instrumentation (the double bass being optional). Alternative additions to a string quartet include clarinet or piano (see clarinet quintet, piano quintet). 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). Besides string quartets and quintets, other closely related chamber music genres include the string trio, and the string sextet. The term string quintet may also refer to a group of five players that specializes in performing such works. The ensemble was standard in 17th century Italy and can be seen as early as 1607 in Claudio Monteverdi's opera, L'Orfeo.

In classical music, a piano quintet is a work of chamber music written for piano and four other instruments, most commonly (since 1842) a string quartet (i.e., two violins, viola, and cello). The term also refers to the group of musicians that plays a piano quintet. The genre flourished during the nineteenth century. Until the middle of the nineteenth century, most piano quintets were scored for piano, violin, viola, cello, and double bass. Following the success of Robert Schumann's Piano Quintet in E♭ major, Op. 44 in 1842, which paired the piano with a string quartet, composers increasingly adopted Schumann's instrumentation, and it was this form of the piano quintet that dominated during the second half of the nineteenth century and into the twentieth century. Among the best known and most frequently performed piano quintets, aside from Schumann's, are Schubert's Trout quintet and the piano quintets of Johannes Brahms, César Franck, Antonín Dvořák and Dmitri Shostakovich.

The Austrian composer Arnold Schoenberg published four string quartets, distributed over his lifetime: String Quartet No. 1 in D minor, Opus 7 (1905), String Quartet No. 2 in F♯ minor, Op. 10 (1908), String Quartet No. 3, Op. 30 (1927), and the String Quartet No. 4, Op. 37 (1936). In addition to these, he wrote several other works for string quartet which were not published. The most notable was his early String Quartet in D major (1897). There was also a Presto in C major (c. 1895), a Scherzo in F major (1897), and later a Four-part Mirror Canon in A major (c. 1933). Finally, several string quartets exist in fragmentary form. These include String Quartet in F major (before 1897), String Quartet in D minor (1904), String Quartet in C major (after 1904), String Quartet Movement (1926), String Quartet (1926), String Quartet in C major (after 1927) and String Quartet No. 5 (1949). Schoenberg also wrote a Concerto for String Quartet and Orchestra in B♭ major (1933): a recomposition of a work by the Baroque composer George Frideric Handel.

The Austrian composer Arnold Schoenberg published four string quartets, distributed over his lifetime: String Quartet No. 1 in D minor, Opus 7 (1905), String Quartet No. 2 in F♯ minor, Op. 10 (1908), String Quartet No. 3, Op. 30 (1927), and the String Quartet No. 4, Op. 37 (1936). In addition to these, he wrote several other works for string quartet which were not published. The most notable was his early String Quartet in D major (1897). There was also a Presto in C major (c. 1895), a Scherzo in F major (1897), and later a Four-part Mirror Canon in A major (c. 1933). Finally, several string quartets exist in fragmentary form. These include String Quartet in F major (before 1897), String Quartet in D minor (1904), String Quartet in C major (after 1904), String Quartet Movement (1926), String Quartet (1926), String Quartet in C major (after 1927) and String Quartet No. 5 (1949). Schoenberg also wrote a Concerto for String Quartet and Orchestra in B♭ major (1933): a recomposition of a work by the Baroque composer George Frideric Handel.