The most distinctive characteristic of that most hallowed of American symbols, the Harley Davidson motorcycle, is the unmistakable, throaty roar of the exhaust. Its music to riders of those beautiful machines, and a noisy nuisance to the unenlightened. Some communities have even tried to ban the bikes, or at least try to muzzle them by trying, sometimes successfully, to enact ordinances against noise.
IN THE FUTURE, when gasoline is all gone and the Harleys are all silently powered by electricity, their unique sound will be a recording played through a speaker made to look like an exhaust pipe, so the bikers will be happy. But everybody will be happy because on the handlebar, right next to the throttle, will be something new, a mute button.