The Orchestre de la Suisse Romande (OSR) is a Swiss symphony orchestra, based in Geneva at the Victoria Hall. In addition to symphony concerts, the OSR performs as the opera orchestra in productions at the Grand Theatre de Geneve. 　　Ernest Ansermet founded the OSR in 1918, with a contingent of 48 players and a season of six months' duration. Besides Swiss musicians, the OSR players initially came from other countries, including Austria, France, Germany and Italy. Ansermet gradually increased the percentage of Swiss musicians in the orchestra, attaining 80% Swiss personnel by 1946. Ansermet remained the music director of the OSR for 49 years, from 1918 to 1967.