A musical keyboard is the set of adjacent depressible levers or keys on a musical instrument. Keyboards contain keys for playing the twelve notes of the Western musical scale, with a combination of larger, longer keys and smaller, shorter keys that repeats at the interval of an octave. Depressing a key on the keyboard makes the instrument produce sounds—either by mechanically striking a string or tine, plucking a string, causing air to flow through a pipe organ, striking a bell, or, on electric and electronic keyboards, completing a circuit. Since the most encountered keyboard instrument is the piano, the keyboard layout is referred to as the piano keyboard; the twelve notes of the Western musical scale are laid out with the lowest note on the left. Because these keys were traditionally covered in ivory they are called the white notes or white keys; the keys for the remaining five notes—which are not part of the C major scale— are raised and shorter. Because these keys receive less wear, they are made of black colored wood and called the black notes or black keys.
The pattern repeats at the interval of an octave. The arrangement of longer keys for C major with intervening, shorter keys for the intermediate semitones dates to the 15th century. Many keyboard instruments dating from before the nineteenth century, such as harpsichords and pipe organs, have a keyboard with the colours of the keys reversed: the white notes are made of ebony and the black notes are covered with softer white bone. A few electric and electronic instruments from the 1960s and subsequent decades have done this; some 1960s electronic organs used reverse colors or gray sharps or naturals to indicate the lower part of a single keyboard divided into two parts, each controlling a different registration or sound. Such keyboards accommodate melody and contrasting accompaniment without the expense of a second manual, were a regular feature in Spanish and some English organs of the renaissance and baroque eras; the break was between middle C and C-sharp, or outside of Iberia between B and C.
Broken keyboards reappeared in 1842 with the harmonium, the split occurring at E4/F4. The reverse-colored keys on Hammond organs such as the B3, C3 and A100 are latch-style radio buttons for selecting pre-set sounds; the chromatic range of keyboard instruments has tended to increase. Harpsichords extended over five octaves in the 18th century, while most pianos manufactured since about 1870 have 88 keys; some modern pianos have more notes. While modern synthesizer keyboards have either 61, 76 or 88 keys, small MIDI controllers are available with 25 notes. Organs have 61 keys per manual, though some spinet models have 44 or 49. An organ pedalboard is a keyboard with long pedals played by the organist's feet. Pedalboards vary in size from 12 to 32 notes. In a typical keyboard layout, black note keys have uniform width, white note keys have uniform width and uniform spacing at the front of the keyboard. In the larger gaps between the black keys, the width of the natural notes C, D and E differ from the width of keys F, G, A and B.
This allows close to uniform spacing of 12 keys per octave while maintaining uniformity of seven "natural" keys per octave. Over the last three hundred years, the octave span distance found on historical keyboard instruments has ranged from as little as 125 mm to as much as 170 mm. Modern piano keyboards ordinarily have an octave span of 164–165 mm. Several reduced-size standards have been marketed. A 15/16 size and the 7/8 DS Standard keyboard developed by Christopher Donison in the 1970s and developed and marketed by Steinbuhler & Company. U. S. pianist Hannah Reimann has promoted piano keyboards with narrower octave spans and has a U. S. patent on the apparatus and methods for modifying existing pianos to provide interchangeable keyboards of different sizes. There have been variations in the design of the keyboard to address musical issues; the earliest designs of keyboards were based on the notes used in Gregorian chant and as such would include B♭ and B♮ both as diatonic "white notes," with the B♮ at the leftmost side of the keyboard and the B♭ at the rightmost.
Thus, an octave would have eight "white keys" and only four "black keys." The emphasis on these eight notes would continue for a few centuries after the "seven and five" system was adopted, in the form of the short octave: the eight aforementioned notes were arranged at the leftmost side of the keyboard, compressed in the keys between E and C. During the sixteenth century, when instruments were tuned in meantone temperament, some harpsichords were constructed with the G♯ and E♭ keys split into t
Carlo Antonio Broggia was an Italian merchant and economist. Author of many works, he was a theoretician of taxation. Carlo was born in the son of Giuseppe Broggia. In 1717 he moved from Naples to Venice where he lived with his uncle for nine years studying business economics. Back to Naples in 1726, he continued his studies under the supervision of Bartolomeo Intieri, he studied philosophy Paolo Mattia Doria and Giambattista Vico. In 1743 Trattato de' tributi, delle monete e del governo politico della sanità was printed. In this book he argues that the tax system should be reformed and based on the individual contributory capacity. By 1744 he wrote La vita civil-economica, remained unpublished. In 1754 Broggia wrote Memoria ad oggetto di varie politiche ed economiche ragioni, a controversial book against the fiscal policy imposed by the minister Leopoldo De Gregorio which took him to exile. Back to Naples in 1761, he wrote Memoria contro il dazio del minutillo in which he expresses his ideas against the export taxes.
He died in his home city of Naples. Broggia, Carlo Antonio. Trattato de' tributi, delle monete, e del governo politico della sanità. Presso Pietro Palombo. Broggia, Carlo Antonio. Memoria ad oggetto di varie politiche ed economiche ragioni e temi di utili raccordi che in causa del monetaggio di Napoli s'espongono e propongono. "Carlo Antonio Broggia". Treccani.it
The Three Valley Museum is a non-profit museum in Durant, Oklahoma. It houses a collection of artifacts regarding the history of Bryan County, it opened in 1976. It is named after the book Queen of the Three Valleys by Henry McCreary, about Durant; the museum is operated by the Durant Historical Society. The museum shows Bryan County from its start in 1873 to the present; the museum's exhibits include a small town exhibit area on the second floor depicting more than 20 businesses and scenes from the early 1900s, including an early law office, doctor's office, child's room and general store. Other exhibits include area transportation history and a Native American Gallery, highlighting the Indian tribes that are located in southeast Oklahoma. Three Valley Museum Three Valley Museum info and video on TravelOK.com Official travel and tourism website for the State of Oklahoma