Theme

A theme is a principal melodic idea — a memorable musical phrase or longer line that serves as the main material of a piece or section. Themes are the building blocks of musical form: composers introduce themes, develop them, vary them, recapitulate them, transform them.

In sonata form, themes are organized into theme groups (first theme group, second theme group). In theme-and-variations form, a single theme is presented and then varied through a series of transformations. In rondo form, a principal theme alternates with contrasting episodes. In symphonic poems, themes can represent characters, ideas, or images.

The theme is what listeners remember. A great theme — Beethoven’s Fifth Symphony opening, Mozart’s Symphony No. 40 first theme, Tchaikovsky’s Romeo and Juliet love theme — becomes part of cultural memory. The composer’s skill in creating, presenting, and developing themes is at the heart of compositional craft.

English/Greek, from Greek thema (‘subject’), from tithēmi (‘to set, place’).

Make themes recognizable. Each statement should establish the theme’s identity clearly — phrasing, dynamics, articulation that emphasize what makes the theme memorable. When themes return, the listener should know.