In the 1980s the work of the composer, teacher and music theorist Alois Hába (1893-1973) was rehabilitated. Hába had been influenced by the work of Arnold Schoenberg, Anton Webern and Ferruccio Busoni, whom he had met in person while living and studying in Vienna and later Berlin. After discovering the world of Arab music, he developed his concept of “athematic” and microtonal music. In collaboration with Petrof and August Foerster, musical instrument manufacturing companies, he built the first version of a quarter tone grand piano in 1923. Aside from this, he constructed several dozen unique quarter tone instruments — guitars, trumpets, clarinets and harmoniums — for performing and promoting his system of microtonal music. Hába saw this system as a way of freeing himself from the traditions of European musical thought, and his unique experimental instruments were pre-conditional to performing concerts of his compositions.