With a real sense of relief or resolution, we now hear the first theme again, followed by all the other themes and other elements of the exposition. There may be minor changes, but in principle everything comes back in its original order. Hence the name for this section — the recapitulation, meaning a step-by-step review.

But there is an important difference: The music now remains in the same key, the tonic key. (In practical terms, this means that the whole second group is relocated in the tonic. To allow for this, the bridge has to be rewritten — often in an imaginative way.) Stability of key in the recapitulation is especially welcome after the instability and restlessness of the development section. Basically, as we have said, sonata form depends on a strong feeling of balance between exposition and recapitulation (A B A′). But it is a weighted balance, because A′ has achieved a new solidity.

The entire B A′ sequence (development and recapitulation) may be repeated. Whether this happens or not, another section in the tonic is often added at the very end, a postmortem or wrap-up for the main action. This optional section is called the coda (in fact, coda is a general term applied to a concluding section in any musical form).

In the following schematic diagram for sonata form, changes of key are shown on a continuous band. Notice the tonal stability of the recapitulation, where the steady horizontal band contrasts with the modulation of the exposition and the fluctuations of the development.

It may not be accidental that the terms used in discussing sonata form resemble those used in discussions of drama. We speak of the “exposition” of a play, where the initial situation is set forth, and of the “development” of the plot. Indeed, sonata form has a dramatic quality compared with the more architectural quality of Baroque music such as a fugue or a ritornello form (compare the chart on page 116 to the one above). In a Classical symphony, the themes seem almost like characters in a play or a novel to whom things are happening. They seem to change, take part in various actions, and react to other themes and musical processes.