September 24 – René Magritte's painting Olympia (a nude portrait of his wife) is stolen from the museum at his former home, rue Esseghem 135 in Brussels, by two armed men. The stolen work is said to be worth about $1.1 million.
October 16 – As part of its celebration of the 100th anniversary of Italian Futurism, the Performa 09 biennial, in collaboration with the Experimental Media and Performing Arts Center (EMPAC) and the San Francisco Museum of Modern Art, premieres a concert at San Francisco Museum of Modern Art whereby it invited Luciano Chessa to direct a reconstruction project to produce accurate replicas of Luigi Russolo's Intonarumori instruments. This project offers the set of 16 original intonarumori (8 noise families of 1–3 instruments each, in various registers) that Russolo built in Milan in the summer of 1913. These intonarumori are physically built by luthier Keith Cary in Winters, California, under Chessa's direction and scientific supervision