The music is William Tell Overture (William Tell Overture), which is the overture to the opera "William Tell" and was written by Italian composer Gioachino Rossini. The opera "William Tell" was composed in 1829. It was the 39th and last opera created by Rossini. After that, he entered a state of semi-retirement, although he continued to create some cantatas, religious music and secular music. .

William Tell's Overture has four parts, with no pause between each part and no truncation at the end. The overture is about 12 minutes long and describes life in the Swiss Alps. The prelude describes dawn in a slow tempo. The second part is the storm, which is about 3 minutes long; the third part is the calm after the storm; the finale starts at 8 minutes and 45 seconds, which is called the marching song of the Swiss Army (the part used by the Hong Kong Racecourse), led by a trumpet The entire orchestra used a super powerful galop to describe the triumphal return of the troops after defeating the Austrian army.

Note: Galop is a fast German dance. Its name comes from the running of the horse. It is in 2/4 time and the dance movements are mainly jumping. It was introduced to Paris in the early 18th century. The upper class and quickly became popular in Europe, it is used in phalanx dances as one of the fastest finishing parts.

You can go and listen to the 4th part that you are curious about (the number in front of html is 0, not O)