“Check this out.” For one edition of my trombone teacher’s weekly dose of music appreciation, he removed a red CD from a jewel case with dark blue liners and placed it in his stereo. Mysterious, rubato piano chords floated out of the speakers; then the bass kicked the time off, and the piano answered it with a simple riff. A drumset quietly simmered beneath it all. Three horns joined in with the piano for a while before giving way to a trumpet solo. “This sounds pretty cool,” my teacher said, fading the music out just as the trumpet solo ended. “He’s not a great trumpet player, though.” I was fourteen years old, and I agreed.