Pipe Humming Easy Vibrato 10-Hole Diatonic Harmonica Unique Design Makes Vibrato a Breeze If you've never seen anything like our new PH-20 Pipe Humming harmonica, there's a good reason. It's the only harp of its kind. The hauntingly beautiful sound of a harmonica vibrato is now as easy as playing the blues. No more struggling to get an air tight seal with your hands. Control is the name of this game. Get a perfect vibrato the very first time you try. Slow, fast, loud, low, flutter, any way you want to make your music sound. Aluminum comb and phosphor bronze reeds combine with special nickel plated pipe cover to create a heavy, rich, deep sound.