Strictly speaking, the Wednesday night program of the Sadler's Wells Ballet did not contain much true ballet. "The Rake's Progress" is more a mimeo-drama than a ballet; and "Dante Sonata" contains a great many elements of modern interpretive dancing. The remaining two selections were the lightweight "Les Patineurs," and the brief pas de deux from Act III of "Sleeping Beauty," which was hardly more than a glimpse.

Nevertheless, the Sadler's Wells Company had ample opportunity to demonstrate the discipline and artistry for which it has been acclaimed. Whatever defeats exist in the program originate with the choreographer, rather than the dancers. "Les Patineurs" is pleasant enough to watch, and it affords Rowena Jackson, Nadia Nerina, and Brian Shaw the opportunity to show off their virtuosity.

"The Rake's Progress," with choreography by Ninette de Valois, is more interesting because it is at least a successful attempt to evoke atmosphere and, more important emotion. Rex Whistler's scenery and costumes are based on Hogarth's famous series of etchings, and the entire ballet is conceived in this spirit. In six scenes we follow the downfall of the young Bake, splendidly danced by Alexander Grant. Especially incisive and brilliant were Brian Shaw, as the Rake's Dancing Master, and Ray Powell, as "The Gentleman with a Rope," an inmate of a London madhouse.

In the all-too-brief Act III pas de deux from "Sleeping Beauty," the true meaning of Sadler's Wells' fame crystalized. The undisputed pinnacle of the evening was Moira Shearer. In this, the only pure classical part of the program, her magnificent body control, intense yet delicate, was completely over-whelming.

In view of the brevity of the pas de deux, however, Ashton's "Dante Sonata," to music by Franz Liszt, was the most important attraction of the evening. A great deal has been read into this ballet that was never intended by the choreographer, but Ashton's instinct toward the abstract rather than narrative form often makes such interpretation possible.

In this ballet the ensemble alone is important, and it is wonderfully eloquent. A tangle of arms and legs, writhing sensuously, and the crucifixion of a white-clad figure in a pool of light epitomize the existence of the Children of Darkness and the Children of Light. Sophie Fedrovitch's decor and costumes are, above all, strikingly simple in design, admirably in keeping with the ballet. This simplicity, the pro-found moral and artistic purpose of Frederick Ashton's choreography, and the trained ability and conviction of the dancers, make "Dante Sonata" an impressively meaningful experience. "Dante Sonata" represents the Salder's Wells Ballet at its non-classical best.