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Melody, Texture & Counterpoint

Theme

Definition

A theme is a main musical idea of a piece, usually a complete melody or phrase, that the music is built around and returns to, often in changed forms.

A theme is a main musical idea of a piece: usually a complete, recognizable melody, a phrase or a period long, that the rest of the music grows from or returns to. If someone asks "How does that piece go?", the tune you hum is probably its theme.

Two treble-clef staves in 3/4, four bars each. The theme has a half note C5 and quarter E5; half note G5 and quarter E5; quarter notes F5, D5, B4; and a dotted half note C5. The variation fills the same bars with eighth notes: C D E F E D; G A G F E C; F E D C B D; then a dotted half note C5.
Top: an original four-bar theme in C major. Bottom: a variation that keeps the theme's main notes on the same beats (C, E, G, E, F, D, B, C) but fills the spaces with running eighth notes.

How themes are used

  • Theme and variations: the theme is stated plainly, then repeated many times with changes of rhythm, harmony, key, texture or character, as in the example's decorated version. You can still hear the theme because its main notes stay in place.
  • Sonata form: the exposition presents a first theme in the home key and a second theme in a new key; the development works with them, and the recapitulation brings them back.
  • Fugue: the theme is called the subject, and it enters in one voice after another.
  • Opera and film: a short theme tied to a character or idea, a leitmotif, comes back whenever that character appears.

Theme, motif and melody

The three words overlap. A motif is a small cell of a few notes; a theme is a larger, complete idea, usually built from motifs. Most themes are melodies, but not every melody is a theme: a theme is a melody that plays a structural role, coming back and being worked on.

Hearing a theme

When you listen to a longer piece, try to memorize its opening theme in the first minute. Then listen for its return: in the same key, in a new key, decorated, in the bass, or broken into pieces. Following the theme is the easiest way to follow the form. The Sonata Detective exercise traces two themes through a model sonata form plan.

Common questions

What is the difference between a theme and a motif?

A motif is a short idea of a few notes. A theme is a complete melodic idea, usually at least a phrase long, that acts as a main subject of a piece.

Practice it: free worksheets