The main mean of creative expression for Degas was the human figure. Degas observed and studied a person in motion in all details, spending many hours with a notebook in his hands. He strove to capture every movement, to catch its slightest nuances on the paintings, to penetrate its mechanics. It is no coincidence that the most famous theme of Degas's works was ballet, a sphere where everything is subordinated to the beauty of movement. 
Degas was a frequent visitor at the Paris Opera and even received a special permission to attend the dance rehearsals of the troupe, which gave the artist the opportunity to depict the theatre's backstage life as well. Degas painted dancers in different situations, from different angles and positions, sometimes the most unusual. The seeming artlessness of the composition and the apparent disinterest of the author create the impression of a him being a spy on someone else's life, these patterns can be found in works such as "Dance Class" (1873-1875), "Dancer on Stage" (1878), "Dancers at Rehearsal" (1879), "Blue Dancers" ( 1890). Degas is proficient in the setting of the angle, the practice of close-ups and variations of lighting. He played with the environment, came up with the role of floors flooded with light, subtly built the relationship of reflections and light sources.

Degas also made a series of works of other participants in the performances, depicting musicians in the orchestra pit and the first rows of spectators: "Ballet from Robert Le Diable" (1871), "Orchestra Musicians"" (1872), "Ballet at the Paris Opera" (1877), etc., which were preceded by several portraits of individual musicians: "Cellist Pilet" (1868), two portraits of the pianist Marie Dihau (1867-1869), "Joseph-Henri Altés" (1868), etc.