Igor Stravinsky is the only composer to have ever been arrested for possession of a dominant seventh chord. Luckily, Stravinsky had the foresight not to return to the Soviet Union from Switzerland in 1920, four years before it morphed into Stalin’s charnel house for non-compliant artists. Instead, this event happened in the land of the free and the brave. In Boston, no less, but this incident was no tea party. It was 1944, and Igor had the temerity to brandish the dominant seventh chord in a concert performance of his arrangement “The Star-Spangled Banner.”