Robin Williams was in rare (okay, typical) form last night at the premiere of his new schmaltzy caper, August Rush. In it, he plays a Fagan-like proprietor of an abandoned theater home to a gang of musical orphans (really). We asked him if he ever played a musical instrument in real life. "Yes," he said, "and I've been asked to stop." Turns out he spent some time playing the sax: "I did a black blues-player set," he said; then he turned into a black blues player: "Man, you just gotta relax! You gotta make love to it, don't hurt it, you know?" But his favorite music, he said, is the music of New York. "Look around you," he exclaimed. "It's like Gershwin flowin'! It's got music, girl, everywhere. Uptown, downtown" -- he turned into a feisty Latina. "Hola, mira, Mami. You got this thing, and it just keeps you movin', ju know? You gotta have it, Papi. You know, leesten, leesten. Iss all crazy! You got to have music!"