For sheer all-star power, tonight is kind of like the Oscars of classical music. Kindly wizard and minimalist composer Terry Riley shows up on Carnegie's main stage with a whole mess of big names in tow, for a special 45th-anniversary performance of his legendary work, "In C." At more than 40 minutes, "In C" is a mesmerizing groundswell built on a pulsing repetition of the top two C keys of the piano. Upon that simple framework, as many as 35 instruments dart in and out, playing in unison then falling away. It doesn't hurt that some of those instruments are played tonight by acclaimed musicians and composers such as Kronos Quartet, Philip Glass, Morton Subotnick, and Dan Zanes.