A lithophone is a musical instrument consisting of a rock or pieces of rock which are struck to produce musical notes. Notes may be sounded in combination (producing harmony) or in succession (melody). The lithophone is an idiophone comparable to instruments such as the glockenspiel, vibraphone, xylophone and marimba.
In the Hornbostel-Sachs classification system, lithophones are designated as '111.22' – directly-struck percussion plaques.
- "Lithophone" | 2020-02-22 | 54 Upvotes 7 Comments
To hear the shape of a drum is to infer information about the shape of the drumhead from the sound it makes, i.e., from the list of overtones, via the use of mathematical theory.
"Can One Hear the Shape of a Drum?" is the title of a 1966 article by Mark Kac in the American Mathematical Monthly which made the question famous, though this particular phrasing originates with Lipman Bers. Similar questions can be traced back all the way to Hermann Weyl . For his paper, Kac was given the Lester R. Ford Award in 1967 and the Chauvenet Prize in 1968.
The frequencies at which a drumhead can vibrate depend on its shape. The Helmholtz equation calculates the frequencies if the shape is known. These frequencies are the eigenvalues of the Laplacian in the space. A central question is whether the shape can be predicted if the frequencies are known; for example, whether a circle-shaped triangle can be recognized in this way. Kac admitted he did not know if it was possible for two different shapes to yield the same set of frequencies. The question of whether the frequencies determine the shape was finally answered in the negative in the early 1990s by Gordon, Webb and Wolpert.
Campanology () is the scientific and musical study of bells. It encompasses the technology of bells – how they are founded, tuned and rung – as well as the history, methods, and traditions of bellringing as an art.
It is common to collect together a set of tuned bells and treat the whole as one musical instrument. Such collections – such as a Flemish carillon, a Russian zvon, or an English "ring of bells" used for change ringing – have their own practices and challenges; and campanology is likewise the study of perfecting such instruments and composing and performing music for them.
In this sense, however, the word campanology is most often used in reference to relatively large bells, often hung in a tower. It is not usually applied to assemblages of smaller bells, such as a glockenspiel, a collection of tubular bells, or an Indonesian gamelan.
- "Campanology" | 2023-04-04 | 52 Upvotes 35 Comments