Degas' first painting devoted solely to the ballet, showing musicians in the orchestra pit with dancers glimpsed past them on stage, dates from 1872 and marked a genuine break with how performance had been painted before: the composition cut off figures at the frame's edge exactly as a photograph might, rejecting the traditional, fully contained portrait or performance scene entirely^[2]. He soon moved past the theatre itself into the Opera's rehearsal halls and practice rooms, where dancers worked through their lessons away from any audience, and it was here that Degas found the subject that would define his career: bodies caught mid-motion, each figure absorbed in her own private effort rather than arranged for a viewer^[3]. Reaching that level of sustained, in-depth observation required an extraordinary volume of preparatory sketching, since capturing each dancer moving independently within a coherent group demanded far more study than a single formal composition would ever need^[3].

The Paris Opera occupied an unusually central place in the social life of the period: nearly every man of standing held a subscription, and subscribers had free run not only of the auditorium but of the wings, the corridors and the dancers' own dressing rooms, a level of backstage access almost unimaginable today^[1]. Degas' friendships with figures inside that world, including the librettist Ludovic Halevy and the Opera bassoonist Desire Dihau, are thought to have opened his own path into the coulisses and rehearsal spaces most outside artists never saw^[1]. What he found there was less the glamour associated with the stage than ordinary labour: dancers stretching, adjusting costumes, waiting, correcting a step at a teacher's instruction, the unglamorous discipline behind a performance the public only ever saw finished.

Degas rarely drew a model as she posed. His preferred method was to watch a subject move through an ordinary action, then wait until she had finished before beginning to draw from memory, arguing that copying what is directly in front of the eye is far less valuable than reconstructing what the mind has retained, since memory and imagination together strip away the tyranny nature otherwise exerts over a drawing^[2]. Applied to dancers, this method let him build figures that read as caught in genuine motion rather than held in an artificial pose, the natural, unguarded gesture of a body at rest set against the highly artificial, trained movements of classical ballet technique^[1]. As his eyesight failed later in life, Degas turned increasingly to sculpture, modelling dancers, horses and nudes in wax from the same accumulated memory of movement, joking to his dealer Ambroise Vollard that failing sight had left him only blind men's work, and Degas remained almost completely blind by the time of his death in 1917^[3].