Answer:
key in three of its four movements.
Step-by-step explanation:
During the Classical and Romantic period, and until today, a symphony is usually played on the same key, along 4 movements.
Sometimes there are variations on the key, especially for the second movement, but traditionally, the four movements form a unity when the key is usually only partially played with a relatively minor or dominant on the second movement, often in a slower tempo.
Since four movements are the common format for symphonies, there are changes in tempo that give a lively continuation of the main theme.
A standard set of tempos as shown below, among the continued use of a key convey a pice the sense of a whole.
Usually, it can be done in this format:
1st movement - allegro (fast) in sonata form
2nd movement - slow
3rd movement - minuet (a dance with three beats in a bar)
4th movement - allegro
Examples:
3) Mozart – Symphony No. 41 (1788)
2) Beethoven – Symphony No. 9 (1824)
1) Beethoven - Symphony No. 3 (1803)