THE Irish-born painter Sir John Lavery (1856-1941) records, in his autobiography, his first meeting with the actress and celebrated beauty Lily Langtry. It was at a charity ball in the 1880s."She," he wrote, "had come as a Bacchante and I as Rembrandt. It was thought that it might be an attraction, as well as a profit, if I painted her portrait, put it up for auction and gave the proceeds to charity, which was done. In addition, a drawing appeared in the Graphic [newspaper] of 'Rembrandt painting the Lily' which added to its value." This amusing occurrence seems somehow typical of London high society near the turn of the century. Fancy dress balls were always a good way of "letting the hair down." Although Langtry - a somewhat racy character of the period - may have been slightly more likely as a "female votary of Bacchus" than Lavery was as the great Dutch master Rembrandt, such disguises were really no more than a humorous form of theater, of pretending. Lavery was a highly successful society portrait painter, and very good at his job. No modernist, he had, nevertheless, studied for a while in Paris. He must have been aware of the French Impressionists. He was definitely an admirer of James McNeill Whistler, the American painter who had ensconced himself in Europe and who plied his own version of softly atmospheric post-Impressionism mixed with a love of Japanese decorativeness and 1890s symbolism. Lavery sometimes emphasized the color arrangement in his paintings in Whistlerian manner, particularly in his paintings titled, "A Girl in Violet and Gold" or "The Grey Drawing-Room." On the whole (even by his own admission), Lavery's overriding aim was to please the sitter, and it is only when an unusual or personal subject offered itself to his brush that his adventurous side shows in its true colors. This must have happened with the Russian ballerina Anna Pavlova. He painted no fewer than six pictures of her, all during the 1910-11 London season in which, among other more conventional dances, she performed her "Dance Bacchanal." This dance was considered rather daring at the time (it might still excite, but would surely not shock, today's ballet-goers), especially as Pavlova was most renowned for her moving but very classical rendering of Fokine's "Dying Swan." "Autumn Bacchanal" dances have long been favorite divertissements in ballet, giving dancers opportunities to show off their dynamism as well as their more-melting finesse. Pavlova was always a strictly classical ballet dancer, and although she did for a while dance with Diaghilev's Ballets Russes, she did not approve of his revolutionary and avant-garde reforms. In her children's book about Pavlova, Robina Beckles Willson describes how Londoners, unused to "such dancing" as the Bacchanal, reacted when they first saw it. It was "an abandoned dance in which Pavlova leapt across the stage in flimsy chiffon, and appeared to be flung to the ground at the end by [her partner] Mordkin." Apparently Pavlova's London audience was "alarmed" by the astonishingly dramatic denouement. But, writes Willson, "Pavlova was unharmed, though it was said that she slapped [Mordkin's] face if he dropped her roughly." The truth is much more likely to be that the two dancers simulated the abandon of this dance with safe skill; to dance in a wild fashion requires, paradoxically, the utmost control. The same goes for painting. It is a measure of Lavery's control that he could paint with such freedom. Pavlova was a considerate and helpful "sitter," though that is hardly the right word. "For a whole morning she posed, almost without resting," writes Lavery, "going through the 'Dance Bacchanal' in slow motion that I might better see the position and the action, explaining that she was doing her necessary exercises and that I must not think that I was exhausting her." To be able to slow down the movements of her dance for the painter shows the kind of control she had. That he produced such an image of fleeting and gracefully ecstatic motion is a tribute to both dancer and painter. Some critics of the time found fault with this painting. One said it was "an abrupt descent from the high level he often attains" and accused it of being "as ugly and uncompromising" as a study of a dancer by Degas seen in the same exhibition. That Degas should be invoked as everything that was terrible about modern painting shows how different attitudes were then from now. In fact Lavery's painting is everything that is summed up by the phrase "premier coup": Its achievement is an effect of apparent spontaneity. It has little in common with Degas's dancers. Its concentration is all on the great ballerina's performance. It is a portrait of a great artiste on stage, as she might have been seen by the audience. The lightness and extravagance of her dancing is, as it would have been in the theater, made even more magical by multicolorful stage lighting, by the costume, and by the fluttering red scarf. Lavery has relished his subject by a display of slashing brushwork. He has also made telling use of the floor shadow, cast in two directions by the stage lights, to emphasize the momentary touch of the dancer's toe on that precise spot. He has disposed her inside the rectangle of his canvas so that she is like an image caught by a camera, just as she passes the viewfinder. Unlike Degas, Lavery celebrated a star; the French artist, working backstage, viewed his dancers as no audience would, and was as interested in them resting, exhausted, as actually dancing. If there is a precedent for Lavery's remarkable, bravura treatment of excited dancing, it is in the drawings French sculptor Rodin made of dancers like Isadora Duncan and Loie Fuller. Lavery knew Rodin, and had visited his studio, when he was invited to be president of the International Society of Sculptors, Painters, and Gravers of which John Lavery was a founder-member and vice-president. This society was designed to give artists an alternative to exhibiting at Britain's Royal Academy. Lavery's interest in it, like his painting of Pavlova, indicates the revolutionary spirit of an artist who might not have been as generally conventional as he was, if it hadn't been for the demands of making a living by his art.