Is it necessary to have duplicates in classical music?

I recognize that there are several extremely useful abilities that are duplicated.

For example, when composing a J-POP song, the B melody and sub-song part jumps to the A melody or the first sub-song with repeated notes, and it is not necessary to repeat the same song.

In the classical music of Sokushi, there are also repeated marks. Specially, in the classical period music of Bara Katsuwa, there are usually repeated notes, for example, the special "earth progression piece" of Mosuda, as well as the duplication notes that are faithful to the actual land observance, and how many double-headed pieces are played at the final meeting. However, it is actually possible to broadcast multiple copies of a reduced-size photo.

The reason for this frequent repeated use of the place in the classical period of Bara Katsuwa is that it is the reason why the place is frequently used repeatedly. The song form is the best example, and the repeated parts have a strong listening power as the first theme overlaps.

On the other hand, there are omissions, duplications, and omissions in the current music gathering. During his stay in Japan, the duplicated features were lost, and each person's time was reduced. I hope that beginners of the steel harp will not have any omissions or omissions in their practice under certain circumstances, so it is important to play several times at the root, but it is important to have a musical performance, but it may be possible to practice and practice under certain circumstances.