Musical development

In classical music, musical development is a process by which a musical idea is communicated in the course of a composition. It refers to the transformation and restatement of initial material. Development is often contrasted with musical variation, which is a slightly different means to the same end. Development is carried out upon portions of material treated in many different presentations and combinations at a time, while variation depends upon one type of presentation at a time.

In this process, certain central ideas are repeated in different contexts or in altered form so that the mind of the listener consciously or unconsciously compares the various incarnations of these ideas. Listeners may apprehend a "tension between expected and real results" (see irony), which is one "element of surprise" in music. This practice has its roots in counterpoint, where a theme or subject might create an impression of a pleasing or affective sort, but delight the mind further as its contrapuntal capabilities are gradually unveiled.

In sonata form, the middle section (between the exposition and the recapitulation) is called the development. Typically, in this section, material from the exposition section is developed. In some older texts, this section may be referred to as free fantasia.

According to the Oxford Companion to Music there are several ways of developing a theme. These include:

The Scherzo movement from Beethoven's Piano Sonata No. 15 in D major, Op 28 (the "Pastoral" Sonata) shows a number of these processes at work on a small scale. Charles Rosen (2002) marvels at the simplicity of the musical material: "The opening theme consists of nothing but four F sharps in descending octaves, followed by a light and simple I/ii/V7/I cadence with a quirky motif repeated four times." These opening eight bars provide all the material Beethoven needs to furnish his development, which takes place in bars 33-48:

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