Sonata Form
Leave home, get lost, find your way back: sonata form is the classic plan for first movements of symphonies, sonatas and string quartets, and Haydn, Mozart and Beethoven used it for most of them. Learn its three parts: the exposition (a first theme in the home key, a contrasting second theme in another key), the development (the themes broken into fragments and pushed through many keys: the conflict) and the recapitulation (both themes home), often closed by a coda. Then follow the keys of Mozart's Symphony No. 40 in G minor (1788), whose second theme arrives in B♭ major and returns in G minor, using chords and two short themes of our own, and send our theme 2 away and back home yourself.
In this lesson you'll
- Name the three parts of sonata form and what happens in each: exposition (theme 1 in the home key, theme 2 in a different key, often the dominant, or the relative major in a minor key), development (fragments through many keys: the conflict) and recapitulation (both themes in the home key), plus the optional coda.
- Follow the keys of Mozart's Symphony No. 40 on the circle of fifths: home in G minor, theme 2 in B♭ major (the relative major, the same two flats, lesson 12) in the exposition, and back in G minor in the recapitulation.
- Play our theme 2 in B♭ major and then in G minor and hear the same tune change key and mood, then make a tiny development by playing its first three notes from different starting notes (D minor, A minor, E minor) and coming back by a chain of fifths.
Music in this lesson
- Symphony No. 40 in G minor, K. 550Mozart · 1788 · first movement (keys followed with generic chords; themes not reproduced)
Remember
Sonata form is a plan in three parts: exposition, development, recapitulation (often followed by a coda); two themes, two keys, one conflict, and the return home makes it all make sense.
In the exposition theme 2 sits away from home, often in the dominant, or in the relative major in a minor-key piece; in the development fragments of the themes travel from key to key; in the recapitulation both themes come back in the home key.
In Mozart's Symphony No. 40 the second theme is in B♭ major in the exposition and returns in G minor in the recapitulation: the same tune in a new key and a new mood; like a leitmotif (lesson 76), a theme is a character that changes as the story ends.