During the past 15 years, a host of exhibitions and monographs have been devoted to Edgar Degas' paintings, drawings, pastels, photographs, prints and sculptures. Perhaps not quite as many as Pablo Picasso, but more than Claude Monet. Now, the Philadelphia Museum of Art, in association with the Detroit Institute of Arts and the American Federation of Arts, weighs in with "Degas and the Dance."

Co-curators Richard Kendall and Jill DeVonyer have brought together beloved standards by the Impressionist master -- from oils such as La Source (Brooklyn Museum of Art) and The Dance Class (Metropolitan Museum of Art) to bronzes like Little Dancer, Aged Fourteen (PMA) -- as well as intriguing canvases and works on paper from private collections that have not been lent to previous shows. And from nooks and crannies all over Paris, Kendall and DeVonyer have assembled documents and works of art related to 19th-century ballet performances and practices that shed light on Degas' originality and biography, not to mention his obsessive and obstinate character.

In one gallery after another, you'll feel you are accompanying the etoiles (soloists) as well as the lowly petits rats (neophytes and walk-ons) at the barre, in rehearsal, and on stage. You'll also meet patrons, dance masters, prima ballerinas and even a stage mother or two. In front of some works, you'll feel exhilarated by the radiant costumes, bright lights and what must have been enchanting music; from other studies, you'll get a sense of the dancers' exhausting daily routine as they spend hour after hour staying in shape and practicing steps.

All of this adds up to one of the most unusual exhibitions to be mounted in a long time. At first, you may feel that "Degas and the Dance" seems to be more about ballet than Impressionism. To be sure, you learn almost everything you ever wanted to know about the opera house on the rue La Peletier, which burned down in 1873, and its replacement, now known as the Palais Garnier, which opened in 1875; the abonnes system that allowed well-heeled men about town to purchase subscriptions that not only afforded them better seats but also access to backstage areas where they could mingle with the dancers and singers (if not a scene in an opera, ballets would be performed on the same bill); and the hardscrabble reality of the performers' lives.

Then too, three models of fragile sets borrowed from the Paris Opera's archives; the original design for the costume worn by Eugenie Fiocre as Princess Nouredda (Princess Leia's precursor) in La Source; and the cover of sheet music composed by Leo Delibes for La Source are the sort of things that add a measure of verisimilitude to this show.

Unlike, say, "Degas at the Races," which was at the National Gallery of Art, Washington, D.C., five years ago, "Degas and the Dance" does not proceed chronologically. Instead, various themes, ranging from "in the classroom" to "the movements of the Greeks," are grouped together. You'll find rough sketches and other studies on display in almost every room. Since these charcoals, pastels, monotypes and even an example of oil paint thinned with turpentine on green paper are executed by an Impressionist, albeit one whose studio practices were traditional, you probably won't think twice about seeing so many "preparatory" sheets. And the artist's expressive lines, the shapes they describe, the poses of the figures, touches of color, highlights and such are riveting.

Of course, it's wonderful to get a sense of how all these works were transformed into finished pastels and oils. Since the different sections of this installation feature, in various combinations, beginnings, middles, and ends, museum-goers are not treated to a conventional grand finale in the last room. However, like a company with a large repertory, say, the Paris Opera, there are lots of opening nights and scenes with scores of the tasks leading up to them.

While executing ballet subjects in all media, the Impressionist master appears to have simultaneously been expressing the trials and tribulations and the pleasures and joys painters and sculptors experience as they create their work. After countless hours and toil, fine artists end up with something which, like choreographed steps and engaging sets and costumes, provides viewers with moments of pleasure. It isn't a long leap to suggest that dance class resembles sketch class; and finished works of art, a staged event.

When Degas made studies of petits rats and paintings of etoiles, he had one foot in the world of performance while the other graced the genre of metaphoric self-portraiture. Magnificently colored pastels and paintings record real and imaginary performances whose subtexts are the artworks. The Parisian's various views of dance classes and rehearsals decidedly evoke the imagery of art academies and other institutions of instruction where models pose and young people learn their craft. Until the end of his life, Degas sketched ballerinas at the barre as if he'd never done that before, an attitude he shared with them. No one had to ask him, "How do you get to the Louvre? He knew the answer, "Practice, practice, practice."

Several writers commenting on "Degas and the Dance" have pointed out that the ballet pictures occupy a large proportion of the artist's oeuvre. Nevertheless, it should be added that he depicted "the horse" over a longer period of time. Early on, equine themes appear in all sorts of situations, including the ballet picture La Source. Throughout his life Degas remained as fascinated by the races as he was by dance.

Sotheby's New York, not that long ago, even had for sale at auction a late, unfinished work of a horse and two Russian dancers. Neither set of quadrupeds -- the animal and the four sashaying legs of the performers -- related to the other nor were these images resolved, for that matter (but that's the sort of thing Richard Kendall brilliantly discussed in his catalogue for the Art Institute of Chicago's "Beyond Impressionism" six years ago). Still, at the end of his career, as at the beginning, the artist continued to weave together the two themes.

And the great fortune of having "Degas and the Dance" on view at the Philadelphia Museum of Art may resolve some of the mystery that surrounds Interior, a painting from ca. 1868-69 in the museum's collections. Kendall and DeVonyar offer new information regarding La Source, executed in 1867-68, and the ballet with this title that had its premiere at the Opera house on rue La Peletier on Nov. 12, 1866. In the catalogue for the show the two curators also reconsider Semiramis Building Babylon, a canvas from ca. 1860-62 belonging to the Musee d'Orsay. They mention that this picture, which includes a horse, is based on Semiramide, a popular 18th- and 19th-century opera. Charles Gounod, a favorite of Degas, and Gioachino Rossini are just two composers among half a dozen who were attracted to this story. Degas was familiar with at least one of them.

Interior appears to belong to this context because it, too, looks like a stage production, probably a popular theatre drama. Why does this matter? Before he became "a painter of dancers," Degas obviously explored a variety of performance-related themes. In the end he opted for working with figures who offered him all sorts of broad, open-ended possibilities. For one, dancers spent their lifetimes posing in positions even more unusual than those associated with classical statues (which he sketched early in his career). Wearing colored costumes, they performed in front of sets depicting beautiful landscapes. And, in the end, their movements related to stories whose complicated scenarios would not be missed if he struck them from any paintings, pastels, monotypes, prints, drawings and sculptures he might execute.

Bravo M. Degas. Please take a curtain call.