VIRTUOSITY AND FAME CAME EASILY TO THE YOUNG VLADIMIR HOROWITZ
-------------------------------------------------------------------- This biographical excerpt is adapted from ''Horowitz,'' to be published next month by William Morrow and Company. During his middle teens, Vladimir, known by the Russian diminutive Volodya, became intrigued with the idea of being a composer-pianist, in the tradition of Liszt and Rachmaninoff. He had accumulated a modest portfolio of original works, which began with his opera transcriptions and extended to ballades and sonatas for piano, songs, and sonatas for violin and cello. But despite his interest and talent for composition, Volodya did not apply himself in harmony and counterpoint classes. Later he admitted that his negligence in academic discipline was one liability in his development. More obstructive to his career as a composer, however, was the devestating effect of the Russian Revolution on him and his family. ''In 24 hours my family lost everything,'' he recalled. ''With my own eyes I saw them throw our piano through the window, into the street! The Communist motto was 'Steal what was stolen,' so they stole everything! All the clothes in the closets were taken. Books, my music, furniture, everything.''