 In 1967, Yaltah and Joel recorded the entire duet repertoire of Mozart in America for Everest Records, the first time ever that this was done by one team of artists.During their annual tours in America and Europe, they gave many charity performances, for such organizations as the Swiss Technical Overseas Relief, for mental hospitals, needy infants in Germany, the World Day of Peace at the Lausanne Swiss National Exposition, and for the opening of United Nations Week in London.Physical illness forced Joel to end his musical career in 1971.