572-G Hot Metal Harp GHohner 572 G Hot Metal Harp Key GHot Metal harp in the key of GPowerful, loud, fast metal and rock can be a sonic steam train. A wall of sound, with fast drums, hard guitars, and strong melodies. When thinking of metal, would you consider the harmonica to be a suitable instrument? Well, it is! And with the Hot Metal, you have the perfect first tester to see how a harmonica would work with your metal sound. But be warned you will fall in love with it.