The recapitulation is a “homecoming” after a long journey. The primary and secondary themes, once in different keys, now unite in the tonic — the conflict resolves.
After the recapitulation often comes the coda — an epilogue that sums up what we have heard. In Beethoven, codas grow enormous, sometimes of equal weight to the preceding sections (the finale of the Eighth Symphony). In Romantic works, the recapitulation is often “transformed” — the theme returns changed, enriched by the experience of the development.
The recapitulation is the third and final section of sonata form (after the exposition and development). Its chief difference from the exposition is tonal: if the secondary theme first appeared in another key, in the recapitulation it returns to the home key, resolving the conflict set up at the start. Sometimes a composer shortens or, conversely, expands the recapitulation, and in a “mirror” recapitulation the themes return in reverse order.
