Variation is a solo dance, generally a part of pas de deux, pas de trois or other, more extensive pieces of a ballet show.
Variations are performed by both danseurs and danseuses. The main purpose of such pieces is to demonstrate the virtuosity of a soloist. For this reason, there is a practice of custom variations, which a certain soloist may perform in different plays.
In terms of music, variation creates a slight change in the pace, melody and tone compared to the main piece, hence adding variety to the main theme. Ballet variation and musical variation became quite close in meaning thanks to Tchaikovsky. He wrote music for ballets by the rules of symphonies; Marius Petipa, who cooperated with him, skillfully found ways to use them and make them varied for his ballets. This technique remained popular in the 20th century and was especially prominent in the works of choreographers who created ballets using symphonic pieces rather than ballet-specific works.