"Main theme" redirects here. For the Pink Floyd song, see Main Theme. For the main theme of The Idol see The Lure.
In music, a subject is the material, usually a recognizable melody, upon which part or all of a composition is based. In forms other than the fugue, this may be known as the theme.
Characteristics
A subject may be perceivable as a complete musical expression in itself, separate from the work in which it is found.[2] In contrast to an idea or motif, a subject is usually a complete phrase or period.[3] The Encyclopédie Fasquelle defines a theme (subject) as "[a]ny element, motif, or small musical piece that has given rise to some variation becomes thereby a theme".[4]
Music based on a single theme is called monothematic, while music based on several themes is called polythematic. Most fugues are monothematic and most pieces in sonata form are polythematic.[8] In the exposition of a fugue, the principal theme (usually called the subject) is announced successively in each voice – sometimes in a transposed form.
In some compositions, a principal subject is announced and then a second melody, sometimes called a countersubject or secondary theme, may occur. When one of the sections in the exposition of a sonata-form movement consists of several themes or other material, defined by function and (usually) their tonality, rather than by melodic characteristics alone, the term theme group (or subject group) is sometimes used.[9][1]
In a fugue, when the first voice has completed the subject, and the second voice is playing the answer, the first voice usually continues by playing a new theme that is called the 'countersubject'. The countersubject usually contrasts with the subject/answer phrase shape.
In a fugue, a countersubject is "the continuation of counterpoint in the voice that began with the subject", occurring against the answer.[13] It is not usually regarded as an essential feature of fugue, however.[14]
The typical fugue opening resembles the following:[13]
Since a countersubject may be used both above and below the answer, countersubjects are usually invertible, all perfect fifths inverting to perfect fourths which required resolution.[15]
Michel, François (ed). (1958–1961). Encyclopédie de la musique, 3 vols. Paris: Fasquelle. (Cited in Nattiez 1990.)
Nattiez, Jean-Jacques (1990). Music and Discourse: Toward a Semiology of Music, translated by Caroline Abbate [from Musicologie générale et sémiologie, 1987]. Princeton: Princeton University Press. ISBN0-691-09136-6 (cloth); ISBN0-691-02714-5.
Randel, Don Michael (ed.) (1999). The Harvard Concise Dictionary of Music and Musicians. Cambridge, Massachusetts: Belknap Press. ISBN0-674-00978-9.
Reti, Rudolph (1951). The Thematic Process in Music. London: Faber and Faber; New York: Macmillan Co. Reprinted, London: Faber and Faber, 1961, Westport, CT: Greenwoid Press, 1978. ISBN0-8371-9875-5.
Reti, Rudolph (1967). Thematic Patterns in Sonatas of Beethoven, edited by Deryck Cooke. London: Faber and Faber; New York: Macmillan Co. Reprinted, New York: Da Capo Press, 1992. ISBN0-306-79714-3.
Rushton, Julia (2001). "Subject Group". The New Grove Dictionary of Music and Musicians, second edition, edited by Stanley Sadie and John Tyrrell. London: Macmillan Publishers.
Schoenberg, Arnold (1975). "My Evolution". In Style and Idea: Selected Writings of Arnold Schoenberg, edited by Leonard Stein, translated by Leo Black, 88. London: Faber and Faber. ISBN0-571-09722-7.