Protests in the concert hall are nothing new: think of the riot-inducing premiere of Stravinsky's The Rite of Spring in 1913 or the backlash at the 1861 premiere of Wagner's Tannhauser. Recently, protesters for a variety of causes have picketed the Metropolitan Opera, the Israel Philharmonic and the Valery Gergiev's Mariinsky Orchestra, among others. It happened again on Oct. 4 at a St. Louis Symphony concert, when a group of demonstrators protesting the police shooting of Michael Brown began to sing, chant and unfurl banners from the balcony, moments before the Brahms Requiem.