A composer (Latin compōnō; literally “one who puts together”) is a person who creates or writes music, which can be vocal music (for a singer or choir), instrumental music (e.g., for solo piano, string quartet, wind quintet or orchestra) or music which combines both instruments and voices (e.g., opera or art song, which is a singer accompanied by a pianist). The core meaning of the term refers to individuals who have contributed to the tradition of Western classical music through creation of works expressed in written musical notation (e.g., sheet music scores).

Many composers are also skilled performers, either as singers, instrumentalists, and/or conductors. Examples of composers who are also well known for their ability as performers include J. S. Bach (an organist), Mozart (violin and piano), and Beethoven, Liszt and Chopin (all skilled pianists). Involvement in practical music-making provides a composer with insight into the diverse musical elements needed for a good piece of music and it can give them practical guidance with their compositions.

In broader usage, “composer” can designate people who participate in other musical traditions who create music, as well as those who create music by means other than written notation: for example, Blues or folk singers and guitarists who create songs through improvisation and recording and popular music writers of musical theatre songs and arrangements. In many popular music genres, such as rock and country, musicians who create new songs are typically called songwriters.

Composers and performers

Since musical notation only incompletely expresses a piece of music, there is a whole continuum of possibilities concerning how much the performer determines the final form of the rendered work in a concert. Even in a classical piece of instrumental music in which all of the melodies, chords, and basslines are written out in musical notation, the performer has a good degree of latitude to add artistic interpretation to the work by varying her articulation and phrasing, choosing how long to make fermatas (held notes) or pauses, and — in the case of bowed string instruments, woodwinds or brass instruments — deciding whether to use expressive effects such as vibrato or portamento. For a singer or instrumental performer, the process of deciding how to perform music that has been previously composed and notated is termed “interpretation”. Different performers’ interpretations of the same work of music can vary widely, in terms of the tempos that are chosen and the playing or singing style or phrasing of the melodies. Composers and songwriters who present their own music are interpreting, just as much as those who perform the music of others. The standard body of choices and techniques present at a given time and a given place is referred to as performance practice, whereas interpretation is generally used to mean the individual choices of a performer.