In 1996, American composer John Adams wrote a whirligig of a piece called “Scratchband.” In its short running time, woodwinds and brass chase each other through thrashing figures so drunk on high spirits that the electric guitar, bass, and percussion can barely keep up. It would be the perfect track to play for anyone who thinks classical music is plodding or stuffy beyond saving—except for the fact that no one owns a legal recording of the music. It’s not as though Adams is ashamed of his daring 12-minute essay in sound. He’s simply been at a loss, for more than a decade, when it comes to identifying a major symphonic work or concerto that “Scratchband” would make sense next to on an 80-minute CD. “I’ve been kind of hedging,” Adams admits, “because it’s hard to find a spot.”