The memoirs of Madame de Genlis first made known the astonishing powers of a poor German soldier on the Jew's harp. This musician was in the service of Frederick the Great, and finding himself one night on duty under the windows of the King, playing the Jew's harp with so much skill, that Frederick, who was a great amateur of music, thought he heard a distinct orchestra. Surprised on learning that such an effect could be produced by a single man with two Jew's harps, he ordered him into his presence; the soldier refused, alleging, that he could only be relieved by his colonel; and that if he obeyed, the king would punish him the next day, for having failed to do his duty. Being presented the following morning to Frederick, he was heard with admiration, and received his discharge and fifty dollars. This artist, whose name Madame de Genlis does not mention, is called Koch; he has not any knowledge of music, but owes his success entirely to a natural taste. He has made his fortune by travelling about, and performing in public and private, and is now living retired at Vienna, at the advanced age of more than eighty years. He used two Jew's harps at once, in the same manner as the peasants of the Tyrol, and produced, without doubt, the harmony of two notes struck at the same moment, which was considered by the musically-curious as somewhat extraordinary, when the limited powers of the instrument were remembered. It was Koch's custom to require that all the lights should be extinguished, in order that the illusion produced by his playing might be increased.