Music has history unto itself, listen to the second movement and read(from wikipedia) about how it came into being and its form.

The Philharmonic Society of London originally commissioned the symphony in 1817. Beethoven started the work in 1818 and finished early in 1824. However, both the words and notes of the symphony have sources dating from earlier in Beethoven’s career.

Second movement

Scherzo: Molto vivace – Presto. Duration approx. 10 mins.

The second movement, a scherzo, is also in D minor, with the opening theme bearing a passing resemblance to the opening theme of the first movement, a pattern also found in the Hammerklavier piano sonata, written a few years earlier. It uses propulsive rhythms and a timpani solo. At times during the piece Beethoven directs that the beat should be one downbeat every three bars, perhaps because of the very fast pace of the majority of the movement which is written in triple time, with the direction ritmo di tre battute (“rhythm of three bars”), and one beat every four bars with the direction ritmo di quattro battute (“rhythm of four bars”).

Beethoven had been criticised before for failing to adhere to standard form for his compositions. He used this movement to answer his critics. Normally, scherzi are written in triple time. Beethoven wrote this piece in triple time, but it is punctuated in a way that, when coupled with the speed of the metre, makes it sound as though it is in quadruple time.

While adhering to the standard ternary design of a dance movement (scherzo-trio-scherzo, or minuet-trio-minuet), the scherzo section has an elaborate internal structure: it is a complete sonata form. Within this sonata form, the first group of the exposition starts out with a fugue.

The contrasting trio section is in D major and in duple (cut) time. The trio is the first time the trombones play in the work.