This opening was unexpected and surprising at the time, during the Classical period. While the strings play these chords pizzicato with rests in between, the wind sustain the chords above. This is followed by a lyrical slow melody, the theme of the adagio, presented by the violins. These few measures are used to build tension in the dominant before the Allegro con brio. And this is often considered a musical joke resulting from Beethoven's experimentation.
The Allegro con brio uses sonata form; the exposition begins with theme A (on the tonic) in a smooth but rhythmic and energetic way, going from pianissimo to fortissimo. After a small bridge comes the exposition of theme B, on the dominant, very melodic in contrast to A, and with an imitative form between the oboe and the flute (Example 2 Track 1 02:09-02:15). The exposition is repeated. The development starts with a variation of theme A, in a minor key. It is interspersed with syncopated motifs using diminished harmony (Example 3 Track 1 05:30-05:44). Then comes the recapitulation, where theme A is now ff, in octaves in the woodwind and strings, and B is in the tonic key. It is the recapitulation that leads us finally to the coda and end of the movement.
The second movement (in F major, subdominant of C), Andante cantabile con moto, is structured in sonata form too. Theme A is introduced in a kind of fugue style, the subject of the 2nd violins is followed by the answer of violas and cellos, later on bassoons, and it is passed around the orchestra (Example 4) (Theme A: Track 2 00:00-00:47). The exposition is linked to the development with a transition or codetta which uses the same rhythmic pedal as the development (Example 5 Track 2 02:04-02:17), that follows a chord sequence accompanying the melody. On the recapitulation the theme is accompanied by the counterpoint of the cello part, which is transferred to the other instruments, as the melody.
