Driving down a quiet street on a summer day with the car windows
down, you see a convertible
approaching from the opposite direction, with the driver playing
her car stereo loudly. Having a
well-trained musician’s ear, you notice that the song you hear is
in a key one semitone (the
interval between two adjacent keys on a piano) above the key in
which the song is typically
heard. You also know that to shift any note by one semitone, the...