Theme music

Theme music is a piece that is often written specifically for a radio program, television program, video game or movie, and usually played during the intro, during title sequence and/or ending credits.

The phrase theme song or signature tune may also be used to refer to a signature song that has become especially associated with a particular performer or dignitary; often used as they make an entrance. The purpose of a theme song is often similar to that of a leitmotif. Such songs can also be used in other ways. One author has made extensive use of them in an effort to explore the feelings behind world views.

Purpose

The purpose of the music is to establish a mood for the show and to provide an audible cue that a particular show is beginning, which was especially useful in the early days of radio (See also interval signal). In some cases, including The Brady Bunch, Gilligan's Island, The Fresh Prince of Bel-Air, both versions of Land of the Lost (1974 and 1991), The Nanny and The Beverly Hillbillies the lyrics of the theme song provide some necessary exposition for people unfamiliar with the show.

Subject (music)

In music, a theme is the material, usually a recognizable melody, upon which part or all of a composition is based. In forms such as the fugue this may be known as the subject.

Characteristics

A theme may be perceivable as a complete musical expression in itself, separate from the work in which it is found (Drabkin 2001). In contrast to an idea or motif, a theme is usually a complete phrase or period (Dunsby 2002). The Encyclopédie Fasquelle defines a theme as "Any element, motif, or small musical piece that has given rise to some variation becomes thereby a theme" (Michel 1958–61).

Thematic changes and processes are often structurally important, and theorists such as Rudolph Reti have created analysis from a purely thematic perspective (Reti 1951; Reti 1967). Fred Lerdahl describes thematic relations as "associational" and thus outside his cognitive-based generative theory's scope of analysis (Lerdahl 2001, 5).

In different types of music

Music based on one 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 (Randel 2002, 429). In the exposition of a fugue, the principal theme (usually called the subject) is announced successively in each voice – sometimes in a transposed form.