Leon Chisholm (Materiality of Musical Instruments, Deutsches Museum)
The standard interface of pianos, organs, and other keyboard instruments, with its pattern of twelve interlocking keys, is a compromise by design. The twelvefold division of the scale into fixed pitches has both shaped and served Western music since medieval times. Yet the notes of this scale form pitch relationships that, for the most part, only approximate the intervals of the natural harmonic series. Over the centuries, scientists, inventors, instrument makers, composers, and musicians have explored myriad ways of accommodating and even overcoming this discrepancy. One strategy for mitigating the limitations of the standard keyboard’s twelve-tone octaves has been to add extra notes to create within the keyboard’s scale microtonal divisions, or intervals smaller than a semitone (the distance between two adjacent notes on the piano). Consideration of some notable early modern examples of microtonal keyboards, including those associated with Nicola Vicentino and Gioseffo Zarlino, can help to contextualize later developments in the nineteenth and twentieth centuries, when microtonal instruments served a variety of aesthetic, philosophical, and scientific ends.
The German scientist Ernst Chladni was one of the pioneers of experimental acoustics. His research on different kinds of vibrations served as the basis for the scientific understanding of sound that later emerged in the 19th century.
In its simplest form the siren consists of two metal disks, each having the same number of regularly spaced concentric holes. The lower disk is mounted on the base of the siren, while the upper disk is mounted on a steel shaft just above it. As air is forced through the system, the upper disk begins to rotate. As it spins, the holes in the two disks briefly line up and then quickly close. Each time they do this, a brief puff of air is released. Each of these puffs acts like a single sound wave, and if enough of them are produced we perceive them as a continuous musical sound.
The Smithsonian's National Museum of American History houses literally millions of objects which preserve and illustrate our nation's rich history. Among the many stories that these objects tell are the ways that Americans have learned about science. This site is designed to help students and teachers explore a unique and beautiful collection of instruments used to teach Acoustics - the science of sound. These historic instruments were designed to be engaging and to challenge students to think in new ways about the physical world.