Michael had suffered from aplastic anemia, a rare blood disorder.
Born in Bavaria, Michael won the Cantelli Conducting Competition in 1961. After serving as an assistant to Herbert von Karajan at the Vienna State Opera, he led the Bremen Opera (1970-78) and the Haydn Orchestra of Balzano and Trento (1977-91). He made his American debut in 1984 at the Seattle Opera, and went on to guest-conduct the Boston Symphony, St. Louis Symphony, Los Angeles Philharmonic, and other major orchestras, as well as conducting regularly at the Metropolitan Opera.
Highlights of his time in Phoenix included a cycle of Mahler symphonies and a series of festivals devoted to Mozart, Beethoven, Tchaikovsky, and the Baroque period. He ended his tenure in May 2004 with a tribute concert featuring pianist Andr_ Watts.
Michael taught at Munich's Musikhochschule.
"Maestro Michael was an unmatched teacher and mentor to so many of us, and his passing is sweet sorrow as we look to begin a new era in our legacy," said Maryellen Gleason, CEO and president of the Phoenix Symphony. "His music-making, particularly with symphonies by Brahms and Mahler, made a significant impact on all who attended his performances."
Michael's successor, Michael Christie, takes up his post this month. The orchestra will pay tribute to Michael at its season-opening concerts on September 10 and 11.