The Exposition Principal Subject (Bridge / Transitional Passage) Second Subject Closing Section The Exposition is the place where the composer 'exposes' all of the musical ideas that he is going to use in the movement. Listen to the opening bars of Mozart's 40th: Click here to hear the example (MIDI File) This is the Principal Subject of the movement. We know this because of two important characteristics: * It is a bold, declamatory theme * It firmly establishes the key (in this case, G minor) Listen to what happens next: Click here to hear the example (MIDI File) Mozart repeats the Principal Subject, except in a slightly modified form. This leads into the Bridge Passage (sometimes known as the Transitional Passage). Notice how this passage seems incomplete. It seems to lead into a different key (modulate), and anticipates a completely new theme. Listen to the next bit: Click here to hear the example (MIDI File) This melody is very different to what has come before. It is the Second Subject. Notice how this theme is much more lyrical and sweeter than the principal subject. It is also in a different key - in this case B flat major. It gradually builds up for the next section: Click here to hear the example (MIDI File) This is known as the Closing Section, because it 'closes' the exposition in the new key, which is B flat major. In many symphonies, the composer introduces completely new material in this section, but in this case, Mozart uses material derived from the Principal Subject and the Bridge Passage. Notice how this section has a conclusive quality about it. (Note that the Closing Section is not an essential part of a sonata-form movement. Many composers choose to omit the Closing Section altogether.) Now let's put all of this together and see how it sounds - click below to hear the Complete Exposition. Click here to hear the example (MIDI File) NOTE: There is an Exposition Repeat at this point. This basically means that the entire Exposition is repeated. Composers in the Classical and Early Romantic periods often put in these Exposition Repeats to help the audience familiarise itself with the music. Nowadays, they are treated as optional - some conductors take the repeats, some don't. For the purposes of our guide, we'll ignore it and move: On to the Development... Previous Page