Free The Sound Book: The Science of the Sonic Wonders of the World by Trevor Cox Page A

organization around the space.
    Leland Sprinkle is not the only person to become obsessed with making the perfect rock instrument. In the nineteenth century, Joseph Richardson took thirteen years to construct a large stone xylophone out of hornfels slate from the English Lake District. According to the Journal of Civilization , Richardson was “a plain unassuming man, with no refinements of education, but possessed of musical talent.” 24 The vast instrument currently resides in the Keswick Museum and Art Gallery in Cumbria, where visitors are actively encouraged to play it.
    The stones of this “rock harmonicon” span two rows over 4 meters (13 feet) long, with steel bars and bells on two upper levels (Figure 2.2). The bass notes are poorly tuned, and the tone varies across the instrument. Some stones ring beautifully, like a wooden xylophone, while others sound like a beer bottle being struck with a stick. A better percussionist might be able to coax a more musical sound than I did. One historical account recalls, “The tones produced are equal in quality, and sometimes superior in mellowness and fulness, to those of a fine piano-forte, under the hand of a skilful player.” 25 One of the key skills of a good percussionist is the ability to make the mallets rebound quickly, so that they do not inhibit the vibration of the instrument. According to the museum’s curator, the whole instrument plays sharp; that is, the frequencies of the notes run higher than the standard scale. To tune the instrument, Joseph Richardson chipped away at each slate bar, gradually raising the frequency of the note. If he removed too much stone, the slate played sharp and there was nothing that he could easily do to flatten the note.

    Figure 2.2 Richardson’s rock harmonicon.
    According to the Journal of Civilization , the Richardson rock harmonicon was so large that it needed three of Joseph Richardson’s sons to play it, “one playing the melody, the next executing a clever working inner part, and the third the fundamental bass. Its power extends to a compass of five octaves and a half . . . extending, in fact, as high as the warble of the lark, down to the deep bass of a funeral bell.” 26
    I managed a plodding rendition of “God Save the Queen”—quite appropriate, since Queen Victoria had requested command performances at Buckingham Palace by what a handbill advertising a public concert described as the “Original Monstre Rock Band.” 27 According to the Times , the first performance was “one of the most extraordinary and novel performances of the Metropolis.” 28 The Richardson family toured Britain and the continent playing music by Handel, Mozart, Donizetti, and Rossini. 29
    John Ruskin, the great Victorian writer and critic, used to own a lithophone made from just eight rocks, and in 2010 a new instrument was constructed for Ruskin’s old home in the English Lake District. Star percussionist Evelyn Glennie gave a celebratory performance on the new lithophone, which has forty-eight keys arranged in a sweeping arc around the player. The instrument contains green slate, blue granite, hornfels, and limestone from various local valleys and mountains. Writing in the Guardian newspaper, Martin Wainwright described the different sounds: “The clinker gives a short, martial note; the green slate a pure, clear, soft sound.” 30
    The team of geographers and musicians that constructed this new instrument also investigated what makes a rock ring. The size, shape, and material determine the frequency of the sound. But what intrigues me most is why some stones go bong while others merely clunk. When a percussionist strikes a stone that rings, the energy is held in the rock for some seconds, with the stone’s vibration being gradually transformed into sound waves in the air that you hear. The rocks that go clunk lose their energy too rapidly within the stone. Good