The revered Italian maestro led the chamber ensemble of Orchestra Mozart, a group of young Italian professional musicians which he co-founded in Bologna in 2005, in works by Pergolesi on November 6 and 7. The concerts launched a three-year project surveying the music of the composer; the 300th anniversary of Pergolesi's birth falls in 2010.
Earlier this fall, illness led Abbado to withdraw from the North American debut performances of the Lucerne Festival Orchestra, another ensemble which he founded (this one in 2003). The three-concert residency was the opening event of Carnegie Hall's 2007-08 season.
Abbado, now 74, was diagnosed with stomach cancer in 2000; after undergoing arduous treatment that included the removal of part of his digestive tract, he returned to the podium and completed his tenure as chief conductor of the Berlin Philharmonic, where he had succeeded Herbert von Karajan. (Abbado's final performances in the post were met with delirious praise.)
A spokesman for Orchestra Mozart, Diego Ravetti, told The New York Times that doctors had ordered Abbado to rest after undergoing unspecified minor surgery that was unrelated to his past condition.