Pairing Schoenberg and Sibelius works for violin and orchestra is brilliant—the pure acid of Schoenberg’s runs makes a perfect foil for the mildly astringent ways of Sibelius. Hahn is an astonishing player, leaping through all of these composers’ headlong chases, succeeding with a show of truly vibrant playing. Whatever reputation these composers have been saddled with over time, here they both seem impossibly and radically alive.