The 1st and 2nd symphonies belong to his first stylistic period, the 3rd to the 8th to his second, the 9th to his third. With the exception of the 6th (the "Pastoral") he sticks to the four-movement structure. The 1st, 2nd, 4th and 7th contain slow introductions in the 1st movement, similar to Haydnís principle, but their importance by far exceeds that of Haydnís model.
The formal structure is more important in the 1st, 2nd, 4th, 7th and 8th; the content is more stressed in the 3rd, 5th and 9th. The 6th ("Pastoral") is a programme symphony. The first movements are always the most important, with the focus lying in the developments, especially since the 3rd, the "Eroica". In the 9th he solves the new problem of introducing vocal music in the Finale by adapting the recitative manner to instrumental writing, using the recitative manner in the violoncello and double basses and quotations from the first 3 movements.
The traditional orchestra of Haydnís period is augmented by a third horn (in the 3rd symphony), in the 5th by piccolo, double bassoon, trombones and in the 9th by piccolo, double bassoon, 3rd and 4th horn, trombones and percussion.