Classical ballet has not been noted for the vigour of its sexual politics though Filippo Taglioni's La Révolte au sérail (1833) is sometimes viewed as an early feminist ballet, with its heroine Zulma and her fellow harem inmates banding together with working women to protest against the tyranny of men. Later and more serious contenders for the genre are Nijinska's Les Biches with its wry analysis of male and female roles both on and off the stage (see Lynn Garafola's study of the ballet in Diaghilev's Ballets Russes, New York, 1989), Les Noces, with its harrowing suggestions of bridal sacrifice, and Page's An American Pattern (1937). Some Soviet ballets have also taken a markedly feminist line in their presentation of powerful heroines, for example in Kasatkina and Vasiliov's Heroic Poem (The Geologists), 1964. Generally, however, the most overtly feminist attitudes to feature in dance have appeared in modern choreography. Isadora Duncan's vision of dance was bound up with her desire for female emancipation and she claimed that her art was ‘symbolic of the freedom of woman and her emancipation from the hidebound conventions that are the warp and woof of New England Puritanism’. She and later performers like Graham, Humphrey, and Wigman moved with a strength and freedom atypical of classical ballerinas, and also presented women in powerful roles. Duncan's prediction in 1902 that future dancers would ‘dance not in the form of a nymph nor fairy nor coquette but in the form of a woman in her greatest and purest expression’ was borne out by the complex and assertive dance heroines created by Graham and others. Significantly, many of the early modern companies were all-female and, even more importantly, were directed and choreographed by women. (In ballet women have exercised power as teachers and ballet mistresses much more than as directors and choreographers.) Later in the century the blurring of distinction between male and female dancers became evident in the choreography of both sexes. Cunningham and some later post-modern choreographers often created works where men and women were given identical movements to perform, while the duet form Contact Improvisation, pioneered by Steve Paxton in the 1970s, became one way of enabling women to master a more active (and traditionally male) role in partnering. Works that directly addressed issues of sexual politics included Jacky Lansley's feminist re-write of Giselle as I Giselle (London, 1981) and the repertories of DV8 and Urban Bush Women. In recent years it has become common for modern dance and some classical ballet to reflect looser social attitudes towards sexuality and gender in their presentation of movement, character, etc. Feminism has become a mainstream part of dance scholarship, reflected in the writings of Susan Foster, among many; seminal publications include Dance Gender and Culture (ed. Helen Thomas, London, 1993) and Sally Banes's Dancing Women (New York, 1998). A parallel development has been the development of male and gay dance studies, reflected in Ramsay Burt's The Male Dancer (London, 1995) and Peter Stoneley's A Queer History of the Ballet (London, 2007).