Scriabin's ten complete piano sonatas offer a fascinating insight into the Russian composer_x001A_s stylistic development. While his first works still fully reflect the late-romantic tradition, the late works keep bursting the bounds oftonality. The boldly outlined, two-movement Fourth Sonata marks a turning point, for it evokes the world of the Poeme de l_x001A_extase with its mystical atmosphere hovering between ethereal rapture and ecstatic flight. The publicationof opus 30 means that all of