In classical music, a piano quintet is a work of chamber music written for piano and four other instruments, most commonly 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 particularly 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.
The piano quintet before 1842
While the related chamber music genres of the piano trio and piano quartet were established in the eighteenth century by Mozart and others, the piano quintet did not come into its own as a genre until the nineteenth century. Its roots extend into the late Classical period, when piano concertos were sometimes transcribed for piano with string quartet accompaniment.
Although Luigi Boccherini composed quintets for piano and string quartet, before 1842 it was more common for the piano to be joined by violin, viola, cello and double bass. Perhaps the best known quintets for this combination of instruments are Franz Schubert's "Trout" Quintet in A major (1819) and Johann Nepomuk Hummel's Piano Quintet in E-flat minor, Op.87 (1802). Other piano quintets using this instrumentation were composed by Jan Ladislav Dussek (1799), Ferdinand Ries (1817), Johann Baptist Cramer (1825, 1832), Henri Jean Rigel (1826), Johann Peter Pixis (ca.1827), Franz Limmer (1832), Louise Farrenc (1839, 1840), and George Onslow (1846, 1848, 1849).
Mozart (in 1784) and Ludwig van Beethoven (in 1796) each composed a quintet for piano and winds, scored for piano, oboe, clarinet, horn, and bassoon, that are sometimes referred to as piano quintets.
Schumann and the Romantic piano quintet
In the middle of the 19th century, Robert Schumann's Piano Quintet in E♭ major, Op. 44 (1842), composed for piano with string quartet, helped make that combination of instruments the default model for the piano quintet. Schumann's choice of scoring reflected developments in musical performance and instrumental design.
By midcentury, the string quartet was regarded as the most prestigious and important chamber music genre, while advances in the design of the piano had expanded its power and dynamic range. Bringing the piano and string quartet together, Schumann's piano quintet took full advantage of the expressive possibilities of these forces in combination, alternating conversational passages between the five instruments with passages in which the combined forces of the strings are massed against the piano. In Schumann's hands, the piano quintet became a genre "suspended between private and public spheres" alternating between "quasi-symphonic and more properly chamber-like elements"--well suited to an era when chamber music was increasingly being performed in large concert halls rather than at private gatherings in intimate spaces. 
Schumann's quintet helped establish the piano quintet as a significant, and quintessentially Romantic, chamber music genre.. It was immediately acclaimed and widely imitated. Johannes Brahms, for example, was persuaded by Clara Schumann, who had played the piano part in the first public performance of her husband's piano quintet, to rework a sonata for two pianos as a piano quintet. The result, the Piano Quintet in F minor (1864), is one of the most frequently performed works of the genre.
Subsequent compositions such as César Franck's Piano Quintet in F minor (1879) and Antonín Dvořák's Piano Quintet #2 in A major, Op. 81 (1887) further solidified the genre as an archetypal "vehicle for Romantic expression."
In the twentieth century, the piano quintet repertoire was expanded with notable contributions by composers such as Béla Bartók, Sergei Taneyev, Louis Vierne, Edward Elgar, Gabriel Fauré, and Dmitri Shostakovich. However, unlike the string quartet, which remained an important chamber music genre for musical experimentation, the piano quintet came to acquire "a somewhat conservative profile, far from major developments" in musical expression.
List of compositions for piano quintet
The following is a partial list of compositions for piano quintet. All works are scored for piano and string quartet unless otherwise noted.
1900 and after
- Robin Stowell; Jonathan Cross (2003). The Cambridge Companion to the String Quartet. Cambridge University Press. p. 324. ISBN 978-0-521-00042-0.
- The quintets for piano, oboe, clarinet, horn, and bassoon composed by Mozart and Beethoven are usually described as "quintets for piano and winds" so as to distinguish them from compositions for piano and four strings.
- Willi Apel (28 November 2003). The Harvard Dictionary of Music. Harvard University Press. p. 699. ISBN 978-0-674-01163-2.
- Smallman, Basil (1996). The Piano Quartet and Quintet: Style, Structure, and Scoring. Clarendon Press. p. 3. ISBN 978-0-19-816640-5.
- Basil Smallman (1996). The Piano Quartet and Quintet: Style, Structure, and Scoring. Clarendon Press. p. 26. ISBN 978-0-19-816640-5.
- John Daverio, 'Robert Schumann: Herald of a "New Poetic Age."' (1997, Oxford), p. 256
- Stowell, Robin The Cambridge Companion to the String Quartet, pp. 323–324.
- Smallman, Basil. The Piano Quartet and Quintet: Style, Structure, and Scoring, p. 53.
-  Rodda, Richard E. "Piano Quintet in F minor, Op. 34," n.p.
- Stowell, Robin. The Cambridge Companion to the String Quartet, p. 325.
- "Goldmark Quintets". Retrieved 4 August 2009.
- "Description Page – Sgambati First Piano Quintet". Edition Silvertrust. Retrieved 4 August 2009.
- "Description Page – Stanford Piano Quintet". Edition Silvertrust. Retrieved 4 August 2009.
- "Description of Disc with Both of Thuille's Quintets". Retrieved 4 August 2009.
- "Description Page – Thuille Piano Quintet in E flat". Edition Silvertrust. Retrieved 4 August 2009.
- "List of works by Charles-Marie Widor". IMSLP.
- "James Aikman – Piano Quintet". Non-Sequitur Music Publishing. Retrieved 17 September 2014.
- "ARENSKI Anton Stéphanovitch Suites pour piano n°1 à 5". abeillemusique.com. Retrieved 24 December 2010.
- "Bacewicz Worklist". Polish Music Information Center. 1998–2003. Retrieved 6 August 2009.
- Trevor Bray (24 June 1965). "Frank Bridge: A Life in Brief ~ Appendix 3: List of Works: 122". Trevor-bray-music-research.co.uk. Retrieved 24 December 2010.
- "FURTWANGLER Piano Quintet [RB]: Classical Reviews- Aug 2002 MusicWeb(UK)". Musicweb-international.com. Retrieved 24 December 2010.
- Alan Rawsthorne: A Bio-Bibliography at Google Books. p. 33.
- Rochberg, George; Gene Rochberg. Five Lines, Four Spaces: The World of My Music at Google Books. p. 111.
- "The Scotsman, 9 November 2007".
- Piano Quintet Op. 1: Scores at the International Music Score Library Project (IMSLP)
- Basil Smallman (1994). The Piano Quartet and Quintet: Style Structure, and Scoring, New York: Oxford University Press. ISBN 0-19-816640-0.