Definição do conceito
[ENG] 78 rpm | Phonograph records are generally described by their diameter in inches (12-inch, 10-inch, 7-inch) (although they were designed in millimeters), the rotational speed in revolutions per minute (rpm) at which they are played (8+1?3, 16+2?3, 33+1?3, 45, 78), and their time capacity, determined by their diameter and speed (LP [long playing], 12-inch disc, 33+1?3 rpm; SP [single], 10-inch disc, 78 rpm, or 7-inch disc, 45 rpm; EP [extended play], 12-inch disc or 7-inch disc, 33+1?3 or 45 rpm); their reproductive quality, or level of fidelity (high-fidelity, orthophonic, full-range, etc.); and the number of audio channels (mono, stereo, quad, etc.). | 78 rpm disc developments : Early disc recordings were produced in a variety of speeds ranging from 60 to 130 rpm, and a variety of sizes. As early as 1894, Emile Berliner´s United States Gramophone Company was selling single-sided 7-inch discs with an advertised standard speed of "about 70 rpm". | One standard audio recording handbook describes speed regulators, or governors, as being part of a wave of improvement introduced rapidly after 1897. A picture of a hand-cranked 1898 Berliner Gramophone shows a governor, and says that spring drives had replaced hand drives. It notes that: The speed regulator was furnished with an indicator that showed the speed when the machine was running so that the records, on reproduction, could be revolved at exactly the same speed...The literature does not disclose why 78 rpm was chosen for the phonograph industry, apparently this just happened to be the speed created by one of the early machines and, for no other reason continued to be used. | In 1912, the Grammophone Company set 78 rpm as their recording standard, based on the average of recordings they had been releasing at the time, and started selling players whose governors had a nominal speed of 78 rpm. By 1925, 78 rpm was becoming standardized across the industry. However, the exact speed differed between places with alternating current electricity supply at 60 hertz (cycles per second, Hz) and those at 50 Hz. Where the mains supply was 60 Hz, the actual speed was 78.26 rpm: that of a 60 Hz stroboscope illuminating 92-bar calibration markings. Where it was 50 Hz, it was 77.92 rpm: that of a 50 Hz stroboscope illuminating 77-bar calibration markings. | SOURCE : Phonograph record. in: WIkipedia. Available at : https://en.wikipedia.org/wiki/Phonograph_record Accessed : 20 sep. 2022
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[ENG] 78 rpm | Any flat disc record, made between about 1898 and the late 1950s and playing at a speed around 78 revolutions per minute is called a "78" by collectors. The materials of which discs were made and with which they were coated were also various; shellac eventually became the commonest material. Generally 78s are made of a brittle material which uses a shellac resin (thus their other name is shellac records). During and after World War II when shellac supplies were extremely limited, some 78 rpm records were pressed in vinyl instead of shellac (wax), particularly the six-minute 12" 78 rpm records produced by V-Disc for distribution to US troops in World War II. | 78s come in a variety of sizes, the most common being 10 inch (25 cm) and 12 inch (30 cm) diameter, and these were originally sold in either paper or card covers, generally with a circular cutout allowing the record label to be seen. Since most 78 rpm discs were issued in paper sleeves with no additional accompanying materials, relatively limited information is provided by the items themselves. | Earliest speeds of rotation varied widely, but by 1910 most records were recorded at about 78 to 80 rpm. In 1925, 78.26 rpm was chosen as a standard for motorized phonographs, because it was suitable for most existing records, and was easily achieved using a standard 3600-rpm motor and 46-tooth gear (78.26 = 3600/46). Thus these records became known as 78s (or "seventy-eights"). This term did not come into use until after World War II when a need developed to distinguish the 78 from other newer disc record formats. Earlier they were just called records, or when there was a need to distinguish them from cylinders, disc records. | The durations of 78 RPM recordings is about three to five minutes per side, depending on the disc size: | 12": ca. four to five minutes | 10": ca. three minutes | As late as the 1970s, some children´s records were released at the 78 rpm speed. | The older 78 format continued to be mass produced alongside the newer formats into the 1950s, but had faded from the scene by 1955. | SOURCE : Yale UNIVERSITY LIBRARY - Irving S. Gilmore Music Library. The history of 78 RPM recordings. Available at : https://web.library.yale.edu/cataloging/music/historyof78rpms Accessed : 20 sep. 2022
[ENG] MARC holdings for 78 RPM recordings | Examples of MARC holdings for 78 RPM recordings in the Historical Sound Recordings Collection || Tag 852 = call number | Indicator 1: 8 = local classification | Indicator 2: 0 = single disc | Indicator 2: 1 = multiple disc set || Tag 866 = volume holdings (for multiple disc set) | Indicator 1: 4 = detailed extent of holdings information | Indicator 2: 1 || ‡b = holding library (‡b mushsr) || ‡t = copy number (‡t 1, ‡t 2, etc.)
|| ‡x = staff note (box number) || SOURCE : Yale UNIVERSITY LIBRARY - Irving S. Gilmore Music Library. The history of 78 RPM recordings. Available at : https://web.library.yale.edu/cataloging/music/78local Accessed : 20 sep. 2022
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[ENG] 78 rpm | 1.78s: (c. 1900 - 1960) | The first disc format was the 10-inch 78 rpm record, pictured above in the center, invented around 1900. (PETER COPELAND
British Library National Sound Archive London ) | .../... || Emil Berliner´s first disc gramophones were wound by hand at somewhere between 60 and 100 rpm. The 7-inch discs lasted a minute or so and had low sound quality. Berliner and his assistant Fred Gaisberg realized that unless the speed was governed, the gramophone would never be more than a novelty. Gaisberg visited a young mechanic who was making clockwork machinery in hoping to use it for sewing machines. This machinery was never successful in sewing machines, but was ideal for gramophones, and it rotated at 78 rpm. (ROGER WORSLEY Haverfordwest Pembrokeshire) | SOURCE: Why 78, 45 and 33 1/3 record formats? Available at : https://www.history-of-rock.com/record_formats.htm Accessed : 20 sep. 2022
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