sentence-transformers/squad huggingface dataset:
Passage: Unwilling to accept and license Columbia's system, in February 1949 RCA Victor, in cooperation of its parent, the Radio Corporation of America, released the first 45 rpm single, 7 inches in diameter with a large center hole. The 45 rpm player included a changing mechanism that allowed multiple disks to be stacked, much as a conventional changer handled 78s. The short playing time of a single 45 rpm side meant that long works, such as symphonies, had to be released on multiple 45s instead of a single LP, but RCA claimed that the new high-speed changer rendered side breaks so brief as to be inaudible or inconsequential. Early 45 rpm records were made from either vinyl or polystyrene. They had a playing time of eight minutes.

Question: What did RCA release to complete against Columbia's LP?

Question: What materials were 45 rpm records made of?

Question: What was the play time of a 45 rpm

Question: What was the size of a RCA Victor 45 rpm?
Passage: One early attempt at lengthening the playing time should be mentioned. At least one manufacturer in the early 1920s, World Records, produced records that played at a constant linear velocity, controlled by Noel Pemberton Billing's patented add-on governor device. As these were played from the outside to the inside, the rotational speed of the records increased as reproduction progressed. This action is similar (although in reverse) to that on the modern compact disc and the CLV version of its predecessor, the Philips Laser Disc.

Question: Who had made an attempt in the 1920s to release a long play time recording?

Question: What caused the constant linear velocity?

Question: What was a unique feature of World Records records?

Question: What currently utilized item was World Records CLV similar to?
Passage: In 1925, 78.26 rpm was chosen as the standard because of the introduction of the electrically powered synchronous turntable motor. This motor ran at 3600 rpm, such that a 46:1 gear ratio would produce 78.26 rpm. In parts of the world that used 50 Hz current, the standard was 77.92 rpm (3,000 rpm with a 77:2 ratio), which was also the speed at which a strobe disc with 77 lines would "stand still" in 50 Hz light (92 lines for 60 Hz). After World War II these records were retroactively known as 78s, to distinguish them 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.

Question: What gear ration creates 78.26 rpm?

Question: In what year was 78.26 rpm chosen as standard?

Question: How many rpm did the electrically powered synchronous turanable motor run at?

Question: Why are these records known as '78s'?
Passage: The older 78 format continued to be mass-produced alongside the newer formats using new materials until about 1960 in the U.S., and in a few countries, such as India (where some Beatles recordings were issued on 78), into the 1960s. For example, Columbia Records' last reissue of Frank Sinatra songs on 78 rpm records was an album called Young at Heart, issued November 1, 1954. As late as the 1970s, some children's records were released at the 78 rpm speed. In the United Kingdom, the 78 rpm single lasted longer than in the United States and the 45 rpm took longer to become popular. The 78 rpm was overtaken in popularity by the 45 rpm in the late 1950s, as teenagers became increasingly affluent.

Question: When did the 45 rpm gain popularity over the 78 rpm

Question: With which crowd did the 45 rpm gain popularity?

Question: At which time were the 79 rpm no longer mass produced?

Question: On which date did Columbia release it's last 78?

Question: What was the last country to phase out the 78 rpm?
Passage: Some of Elvis Presley's early singles on Sun Records might have sold more copies on 78 than on 45. This is because the majority of those sales in 1954–55 were to the "hillbilly" market in the South and Southwestern United States, where replacing the family 78 rpm player with a new 45 rpm player was a luxury few could afford at the time. By the end of 1957, RCA Victor announced that 78s accounted for less than 10% of Presley's singles sales, essentially announcing the death throes of the 78 rpm format. The last Presley single released on 78 in the United States was RCA Victor 20-7410, I Got Stung/One Night (1958), while the last 78 in the UK was RCA 1194, A Mess Of Blues/Girl Of My Best Friend (1960).

Question: What percentage of Elvis Presley's single sales were of 78s?

Question: What was the last 78 released in the UK by RCA?

Question: Why did Elvis sales of 78s perform so well in the Southern States?

Question: On which label did Elvis release his early singles?

Question: What was the last Elvis Presley single released on 78?
Passage: After World War II, two new competing formats came onto the market and gradually replaced the standard "78": the 33 1⁄3 rpm (often just referred to as the 33 rpm), and the 45 rpm (see above). The 33 1⁄3 rpm LP (for "long-play") format was developed by Columbia Records and marketed in June 1948. RCA Victor developed the 45 rpm format and marketed it in March 1949, each pursuing their own r&d in secret. Both types of new disc used narrower grooves, intended to be played with smaller stylus—typically 0.001 inches (25 µm) wide, compared to 0.003 inches (76 µm) for a 78—so the new records were sometimes called Microgroove. In the mid-1950s all record companies agreed to a common recording standard called RIAA equalization. Prior to the establishment of the standard each company used its own preferred standard, requiring discriminating listeners to use pre-amplifiers with multiple selectable equalization curves.

Question: What two formats replaced the 78?

Question: Who developed the 33 1/3 rpm LP?

Question: When did the 33 1/3 rpm hit the market?

Question: When did RCA release their 45 rpm format?

Question: When were RIAA standards established?
Passage: Some recordings, such as books for the blind, were pressed at 16 2⁄3 rpm. Prestige Records released jazz records in this format in the late 1950s; for example, two of their Miles Davis albums were paired together in this format. Peter Goldmark, the man who developed the 33 1⁄3 rpm record, developed the Highway Hi-Fi 16 2⁄3 rpm record to be played in Chrysler automobiles, but poor performance of the system and weak implementation by Chrysler and Columbia led to the demise of the 16 2⁄3 rpm records. Subsequently, the 16 2⁄3 rpm speed was used for narrated publications for the blind and visually impaired, and were never widely commercially available, although it was common to see new turntable models with a 16 rpm speed setting produced as late as the 1970s.

Question: What was 16 2/3 rpm speed used for?

Question: Who developed the 33 1/3 rpm speed record?

Question: What record format was created for use in Chrysler automobiles?

Question: Why did Chrysler discontinue use of the Hifi 16 2/3 rpm record?

Question: To the end of which era could you find 16 rpm setting on record players?
Passage: The commercial rivalry between RCA Victor and Columbia Records led to RCA Victor's introduction of what it had intended to be a competing vinyl format, the 7-inch (175 mm) 45 rpm disc. For a two-year period from 1948 to 1950, record companies and consumers faced uncertainty over which of these formats would ultimately prevail in what was known as the "War of the Speeds". (See also format war.) In 1949 Capitol and Decca adopted the new LP format and RCA gave in and issued its first LP in January 1950. The 45 rpm size was gaining in popularity, too, and Columbia issued its first 45s in February 1951. By 1954, 200 million 45s had been sold.

Question: Which company lost the "War of the Speeds"?

Question: What speed ultimantly ended up winning the war of the speeds?

Question: Over which years did the "War of the Speeds" last?

Question: By 1945 what was the total sale of 45s?

Question: Which two companies were involved in the "War of the Speeds"?
Passage: Eventually the 12-inch (300 mm) 33 1⁄3 rpm LP prevailed as the predominant format for musical albums, and 10-inch LPs were no longer issued. The last Columbia Records reissue of any Frank Sinatra songs on a 10-inch LP record was an album called Hall of Fame, CL 2600, issued on October 26, 1956, containing six songs, one each by Tony Bennett, Rosemary Clooney, Johnnie Ray, Frank Sinatra, Doris Day, and Frankie Laine. The 10-inch LP however had a longer life in the United Kingdom, where important early British rock and roll albums such as Lonnie Donegan's Lonnie Donegan Showcase and Billy Fury's The Sound of Fury were released in that form. The 7-inch (175 mm) 45 rpm disc or "single" established a significant niche for shorter duration discs, typically containing one item on each side. The 45 rpm discs typically emulated the playing time of the former 78 rpm discs, while the 12-inch LP discs eventually provided up to one half-hour of recorded material per side.

Question: What format of LPs was discontinued?

Question: What was the significance of October 26th, 1956?

Question: In which country did the 10 in LP exist the longest?

Question: Which format offered up to 1/2 an hour of recordings per side?

Question: Did the 45 rpm or 12 inch disc offer longer playing time?
Passage: The 45 rpm discs also came in a variety known as extended play (EP), which achieved up to 10–15 minutes play at the expense of attenuating (and possibly compressing) the sound to reduce the width required by the groove. EP discs were cheaper to produce, and were used in cases where unit sales were likely to be more limited or to reissue LP albums on the smaller format for those people who had only 45 rpm players. LP albums could be purchased 1 EP at a time, with four items per EP, or in a boxed set with 3 EPs or 12 items. The large center hole on 45s allows for easier handling by jukebox mechanisms. EPs were generally discontinued by the late 1950s in the U.S. as three- and four-speed record players replaced the individual 45 players. One indication of the decline of the 45 rpm EP is that the last Columbia Records reissue of Frank Sinatra songs on 45 rpm EP records, called Frank Sinatra (Columbia B-2641) was issued on December 7, 1959. The EP lasted considerably longer in Europe, and was a popular format during the 1960s for recordings by artists such as Serge Gainsbourg and the Beatles.

Question: What do the initials EP stand for?

Question: Why were 45s more popular with jukeboxes?

Question: What format was phased out by the end of the 1950s?

Question: What was a benefit of EPs over LPs?
Passage: From the mid-1950s through the 1960s, in the U.S. the common home record player or "stereo" (after the introduction of stereo recording) would typically have had these features: a three- or four-speed player (78, 45, 33 1⁄3, and sometimes 16 2⁄3 rpm); with changer, a tall spindle that would hold several records and automatically drop a new record on top of the previous one when it had finished playing, a combination cartridge with both 78 and microgroove styli and a way to flip between the two; and some kind of adapter for playing the 45s with their larger center hole. The adapter could be a small solid circle that fit onto the bottom of the spindle (meaning only one 45 could be played at a time) or a larger adaptor that fit over the entire spindle, permitting a stack of 45s to be played.

Question: What three speeds were sound on most home stereos in the mid 1950's?

Question: What feature of 45s required an adapter in most home stereos?

Question: What feature was found on more home stereos that allowed continuous play between records?

Question: What format was less common but could sometimes be found on home stereos?
Passage: RCA 45s were also adapted to the smaller spindle of an LP player with a plastic snap-in insert known as a "spider". These inserts, commissioned by RCA president David Sarnoff and invented by Thomas Hutchison, were prevalent starting in the 1960s, selling in the tens of millions per year during the 45 rpm heyday. In countries outside the U.S., 45s often had the smaller album-sized holes, e.g., Australia and New Zealand, or as in the United Kingdom, especially before the 1970s, the disc had a small hole within a circular central section held only by three or four lands so that it could be easily punched out if desired (typically for use in jukeboxes).

Question: Wy did records outside of the US often have small holes with the ability to punch out the center?

Question: What were the plastic inserts which would adapt 45s to the smaller spindle of an LP player called?

Question: What invention did Thomas Hutchinson introduce?

Question: Whom were the adaptable inserts for 45s to LPs commissioned by?

Question: How many spiders were sold in the 45 rpm heydays?
Passage: The term "high fidelity" was coined in the 1920s by some manufacturers of radio receivers and phonographs to differentiate their better-sounding products claimed as providing "perfect" sound reproduction. The term began to be used by some audio engineers and consumers through the 1930s and 1940s. After 1949 a variety of improvements in recording and playback technologies, especially stereo recordings, which became widely available in 1958, gave a boost to the "hi-fi" classification of products, leading to sales of individual components for the home such as amplifiers, loudspeakers, phonographs, and tape players. High Fidelity and Audio were two magazines that hi-fi consumers and engineers could read for reviews of playback equipment and recordings.

Question: What term was coined to differentiate better sounding products in the 1920s?

Question: What magazines provided reviews for audio equipment?

Question: What happened in 1958 that changed the home music scene?

Question: During what years did the term HiFi take off with engineers?

Question: What term would be used when one said they produced perfect sound reproduction?
Passage: Stereophonic sound recording, which attempts to provide a more natural listening experience by reproducing the spatial locations of sound sources in the horizontal plane, was the natural extension to monophonic recording, and attracted various alternative engineering attempts. The ultimately dominant "45/45" stereophonic record system was invented by Alan Blumlein of EMI in 1931 and patented the same year. EMI cut the first stereo test discs using the system in 1933 (see Bell Labs Stereo Experiments of 1933) although the system was not exploited commercially until much later.

Question: What did Alan Blumlein event?

Question: When did EMI create the first stereo discs?

Question: What was the benefit of 45/45 stereo sound?

Question: What year was stereo sound patented?

Question: How was the commercial success of stereo sound in the 1930s?
Passage: The development of quadraphonic records was announced in 1971. These recorded four separate sound signals. This was achieved on the two stereo channels by electronic matrixing, where the additional channels were combined into the main signal. When the records were played, phase-detection circuits in the amplifiers were able to decode the signals into four separate channels. There were two main systems of matrixed quadraphonic records produced, confusingly named SQ (by CBS) and QS (by Sansui). They proved commercially unsuccessful, but were an important precursor to later surround-sound systems, as seen in SACD and home cinema today.

Question: What did quadraphonic recording feature?

Question: What was the newest break through in home sound systems in 1971?

Question: How would the commercial success of quadraphonic records be defined?

Question: What did developments in quadraphonic recordings inspire?
Passage: A different format, CD-4 (not to be confused with compact disc), by RCA, encoded the front-rear difference information on an ultrasonic carrier, which required a special wideband cartridge to capture it on carefully calibrated pickup arm/turntable combinations. CD-4 was even less successful than the two matrixed formats. (A further problem was that no cutting heads were available that could handle the HF information. That was remedied by cutting at half the speed. Later, the special half-speed cutting heads and equalization techniques were employed to get a wider frequency response in stereo with reduced distortion and greater headroom.)

Question: What was a major issue with CD-4 technology?

Question: How widespread was the success of CD-4 format?

Question: What format was less successful than quadraphonic?

Question: What were potential benefits of the CD-4 format?

Question: Who created the CD-4 format?
Passage: Under the direction of recording engineer C. Robert Fine, Mercury Records initiated a minimalist single microphone monaural recording technique in 1951. The first record, a Chicago Symphony Orchestra performance of Pictures at an Exhibition, conducted by Rafael Kubelik, was described as "being in the living presence of the orchestra" by The New York Times music critic. The series of records was then named Mercury Living Presence. In 1955, Mercury began three-channel stereo recordings, still based on the principle of the single microphone. The center (single) microphone was of paramount importance, with the two side mics adding depth and space. Record masters were cut directly from a three-track to two-track mixdown console, with all editing of the master tapes done on the original three-tracks. In 1961, Mercury enhanced this technique with three-microphone stereo recordings using 35 mm magnetic film instead of half-inch tape for recording. The greater thickness and width of 35 mm magnetic film prevented tape layer print-through and pre-echo and gained extended frequency range and transient response. The Mercury Living Presence recordings were remastered to CD in the 1990s by the original producer, Wilma Cozart Fine, using the same method of 3-to-2 mix directly to the master recorder.

Question: For which company did C. Robert Fine work for?

Question: What benefits were found in using the 35mm magnetic film?

Question: Who developed the 3-to-2 mix to create lifelike recordings?

Question: Which microphone hold the most importance in 3 microphone recording?

Question: In which year did Mercury begin 3 channel stereo recording?
Passage: Through the 1960s, 1970s, and 1980s, various methods to improve the dynamic range of mass-produced records involved highly advanced disc cutting equipment. These techniques, marketed, to name two, as the CBS DisComputer and Teldec Direct Metal Mastering, were used to reduce inner-groove distortion. RCA Victor introduced another system to reduce dynamic range and achieve a groove with less surface noise under the commercial name of Dynagroove. Two main elements were combined: another disk material with less surface noise in the groove and dynamic compression for masking background noise. Sometimes this was called "diaphragming" the source material and not favoured by some music lovers for its unnatural side effects. Both elements were reflected in the brandname of Dynagroove, described elsewhere in more detail. It also used the earlier advanced method of forward-looking control on groove spacing with respect to volume of sound and position on the disk. Lower recorded volume used closer spacing; higher recorded volume used wider spacing, especially with lower frequencies. Also, the higher track density at lower volumes enabled disk recordings to end farther away from the disk center than usual, helping to reduce endtrack distortion even further.

Question: What technique were used to reduce inner-groove distortion?

Question: Who developed the Dynagroove format?

Question: Why did some music lovers frown upon diaphragming?

Question: What did closer groove spacing result in?

Question: What would be found with higher recorded volumes?
Passage: Also in the late 1970s, "direct-to-disc" records were produced, aimed at an audiophile niche market. These completely bypassed the use of magnetic tape in favor of a "purist" transcription directly to the master lacquer disc. Also during this period, half-speed mastered and "original master" records were released, using expensive state-of-the-art technology. A further late 1970s development was the Disco Eye-Cued system used mainly on Motown 12-inch singles released between 1978 and 1980. The introduction, drum-breaks, or choruses of a track were indicated by widely separated grooves, giving a visual cue to DJs mixing the records. The appearance of these records is similar to an LP, but they only contain one track each side.

Question: How did Disco Eye-Cued system benefit DJs?

Question: How did Disco Eye-Cued sysems differ from LPs?

Question: When was the Disco Eye-Cued System developed?

Question: What were direct to disc recordings expected to product?

Question: When were 'half speed' and 'digitally remastered' recordings being released?
Passage: The mid-1970s saw the introduction of dbx-encoded records, again for the audiophile niche market. These were completely incompatible with standard record playback preamplifiers, relying on the dbx compandor encoding/decoding scheme to greatly increase dynamic range (dbx encoded disks were recorded with the dynamic range compressed by a factor of two in dB: quiet sounds were meant to be played back at low gain and loud sounds were meant to be played back at high gain, via automatic gain control in the playback equipment; this reduced the effect of surface noise on quiet passages). A similar and very short-lived scheme involved using the CBS-developed "CX" noise reduction encoding/decoding scheme.

Question: What was required for quality playback of DBX recordings?

Question: When were DBX recordings released?

Question: How compatible were DBX encoded recordings with prior technologies?

Question: What was the intention of DBX encoded recordings?

Question: What did CBS develop in order to reduce outside noise?
Passage: ELPJ, a Japanese-based company, sells a laser turntable that uses a laser to read vinyl discs optically, without physical contact. The laser turntable eliminates record wear and the possibility of accidental scratches, which degrade the sound, but its expense limits use primarily to digital archiving of analog records, and the laser does not play back colored vinyl or picture discs. Various other laser-based turntables were tried during the 1990s, but while a laser reads the groove very accurately, since it does not touch the record, the dust that vinyl attracts due to static electric charge is not mechanically pushed out of the groove, worsening sound quality in casual use compared to conventional stylus playback.

Question: What company out of Japan offered laser turntables that read vinyl discs optically?

Question: What was a benedit of laser read discs?

Question: What was a drawback of laser read discs?

Question: What was the primary use of laser read discs?

Question: What was a major issue for laser read discs?
Passage: In some ways similar to the laser turntable is the IRENE scanning machine for disc records, which images with microphotography in two dimensions, invented by a team of physicists at Lawrence Berkeley Laboratories. IRENE will retrieve the information from a laterally modulated monaural grooved sound source without touching the medium itself, but cannot read vertically modulated information. This excludes grooved recordings such as cylinders and some radio transcriptions that feature a hill-and-dale format of recording, and stereophonic or quadraphonic grooved recordings, which utilize a combination of the two as well as supersonic encoding for quadraphonic.

Question: Who is Irene?

Question: Where was IRENE developed?

Question: What is the primary use of IRENE?

Question: Can IRENE read vertically modulated information?

Question: Does IRENE require the ability to touch the media?