RICHARD AND COSIMA WAGNER:
BIOGRAPHY OF A MARRIAGE
by Geoffrey Skelton; Houghton Mifflin; 319 pages; $14.95
She was 26, an illegitimate daughter of Franz Liszt, wife of Pianist and Conductor Hans von Bülow, a quick, intense, yearningly serious votary of high German romanticism. He was 51, notorious throughout Europe as a musical and political revolutionary, separated from his wife of 29 years, his life a "perpetual hurricane" of controversies, conniving and debts, a questing genius who had gone through women as if trying out musical themes, searching for the one who would sing to...