Claudio Abbado, a star in the great generation of Italian conductors, died Monday at his home in Bologna. He was 80 and had suffered a long illness. Abbado made his debut in 1960 at La Scala in his home city of Milan and went on to be its music director for nearly 20 years. Among his many other positions were music director of the Vienna State Opera, the Berlin Philharmonic, the London Symphony Orchestra, and principal guest conductor of the Chicago Symphony Orchestra. In an unusually personal message of condolence, Italy's President Giorgio Napolitano said Abbado had "honored the great musical tradition of our country in Europe and the rest of the world." In its tributes, La Scala hailed Abbado for leaving his mark as a conductor "without confines, as a musician without preconceptions, as a man of theater ready to risk, as a man of thought open to the world."