A Pierrot ensemble is a musical ensemble comprising flute, clarinet, violin, cello and piano. This ensemble is named after 20th-century composer Arnold Schoenberg’s seminal work Pierrot Lunaire, which includes the quintet of instruments above with a narrator (usually performed by a soprano).
The quintet of instruments used in Pierrot Lunaire has been used in the twentieth century by different groups, such as The Fires of London, who formed in 1965 as "The Pierrot Players" to perform Pierrot Lunaire, and continued to concertize with a varied classical and contemporary repertory. This group began to perform works arranged for these instruments and commission new works.
While standard chamber ensembles (such as string quartets or piano trios) continued to be extremely popular among 20th-century composers, the Pierrot ensemble represents an example of the many kinds of non-standard chamber ensembles that have been used in classical music since the beginning of the 20th century.
The number of compositions written for Pierrot Ensemble is limited by the inherent unbalance of the ensemble (two strings, plus two winds, plus piano). More frequent are works that introduce additional instruments, typically more strings, and especially percussion which obtains a small, and inexpensive, chamber ensemble with three families of instruments represented.
Doublings are a standard compositional device used to extend an ensemble instrumental color. In Schoenberg's Pierrot Lunaire, the flutist is asked to play piccolo, the clarinetist is asked to play bass clarinet. Other common doublings might include E♭ clarinet (as in Carter's Triple Duo), alto flute.
Christopher Dromey, The Pierrot Ensembles: Chronicle and Catalogue, 1912-2012 (London: Plumbago, 2013).