The theme of the 2012 Salkind Festival of duo pianism (properly known as the San Francisco International Music Festival) is Paris in its golden age, 1870-1912, along with a celebration of the sesquicentennial of Debussy’s birth. You’ll be able to hear world-class piano duos take on La Mer, Nuages, La Valse, The Rite of Spring, and more at the San Francisco Conservatory of Music. But perhaps the most intriguing event, in a very full weekend, is the afternoon (4 p.m.) concert on July 7, when eight dancers will perform Mark Foehringer’s choreography to duo accompaniment, evoking the famous composer-choreographer collaborations of the era.