romikgosai/squad_modified_2 huggingface dataset:
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.

Q1: What did quadraphonic recording feature?
A1: recorded four separate sound signals.
Q2: What was the newest break through in home sound systems in 1971?
A2: development of quadraphonic records
Q3: How would the commercial success of quadraphonic records be defined?
A3: commercially unsuccessful
Q4: What did developments in quadraphonic recordings inspire?
A4: later surround-sound systems
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.)

Q1: What was a major issue with CD-4 technology?
A1: no cutting heads were available that could handle the HF information
Q2: How widespread was the success of CD-4 format?
A2: even less successful than the two matrixed formats
Q3: What format was less successful than quadraphonic?
A3: CD-4
Q4: What were potential benefits of the CD-4 format?
A4: reduced distortion and greater headroom
Q5: Who created the CD-4 format?
A5: RCA
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.

Q1: For which company did C. Robert Fine work for?
A1: Mercury Records
Q2: What benefits were found in using the 35mm magnetic film?
A2: prevented tape layer print-through and pre-echo and gained extended frequency range and transient response
Q3: Who developed the 3-to-2 mix to create lifelike recordings?
A3: Mercury
Q4: Which microphone hold the most importance in 3 microphone recording?
A4: The center
Q5: In which year did Mercury begin 3 channel stereo recording?
A5: 1955
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.

Q1: What technique were used to reduce inner-groove distortion?
A1: CBS DisComputer and Teldec Direct Metal Mastering
Q2: Who developed the Dynagroove format?
A2: RCA Victor
Q3: Why did some music lovers frown upon diaphragming?
A3: unnatural side effects
Q4: What did closer groove spacing result in?
A4: Lower recorded volume
Q5: What would be found with higher recorded volumes?
A5: wider spacing
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.

Q1: How did Disco Eye-Cued system benefit DJs?
A1: visual cue to DJs mixing the records
Q2: How did Disco Eye-Cued sysems differ from LPs?
A2: only contain one track each side
Q3: When was the Disco Eye-Cued System developed?
A3: late 1970s
Q4: What were direct to disc recordings expected to product?
A4: a "purist" transcription
Q5: When were 'half speed' and 'digitally remastered' recordings being released?
A5: late 1970s
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.

Q1: What was required for quality playback of DBX recordings?
A1: automatic gain control
Q2: When were DBX recordings released?
A2: mid-1970s
Q3: How compatible were DBX encoded recordings with prior technologies?
A3: completely incompatible with
Q4: What was the intention of DBX encoded recordings?
A4: reduced the effect of surface noise on quiet passages
Q5: What did CBS develop in order to reduce outside noise?
A5: "CX" noise reduction
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.

Q1: What company out of Japan offered laser turntables that read vinyl discs optically?
A1: ELPJ
Q2: What was a benedit of laser read discs?
A2: eliminates record wear
Q3: What was a drawback of laser read discs?
A3: degrade the sound
Q4: What was the primary use of laser read discs?
A4: archiving of analog records
Q5: What was a major issue for laser read discs?
A5: dust
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.

Q1: Who is Irene?
A1: scanning machine for disc records
Q2: Where was IRENE developed?
A2: Lawrence Berkeley Laboratories
Q3: What is the primary use of IRENE?
A3: retrieve the information
Q4: Can IRENE read vertically modulated information?
A4: cannot read vertically modulated information
Q5: Does IRENE require the  ability to touch the media?
A5: without touching the medium
Terms such as "long-play" (LP) and "extended-play" (EP) describe multi-track records that play much longer than the single-item-per-side records, which typically do not go much past four minutes per side. An LP can play for up to 30 minutes per side, though most played for about 22 minutes per side, bringing the total playing time of a typical LP recording to about forty-five minutes. Many pre-1952 LPs, however, played for about 15 minutes per side. The 7-inch 45 rpm format normally contains one item per side but a 7-inch EP could achieve recording times of 10 to 15 minutes at the expense of attenuating and compressing the sound to reduce the width required by the groove. EP discs were generally used to make available tracks not on singles including tracks on LPs albums in a smaller, less expensive format for those who had only 45 rpm players. The large center hole on 7-inch 45 rpm records allows for easier handling by jukebox mechanisms. The term "album", originally used to mean a "book" with liner notes, holding several 78 rpm records each in its own "page" or sleeve, no longer has any relation to the physical format: a single LP record, or nowadays more typically a compact disc.

Q1: What terms are used for recording with more than one track?
A1: long-play" (LP) and "extended-play" (EP
Q2: What is a typical max playing time of an LP?
A2: forty-five minutes
Q3: Which format is cheaper, LP or EP?
A3: LPs
Q4: Which format held recordings ranging from 10 to 15 minutes?
A4: 7-inch EP
Q5: What was a normal play time per side for LPs?
A5: 22 minutes
In March 1949, as RCA released the 45, Columbia released several hundred 7 inch 33 1/3 rpm small spindle hole singles. This format was soon dropped as it became clear that the RCA 45 was the single of choice and the Columbia 12 inch LP would be the 'album' of choice. The first release of the 45 came in seven colors: black 47-xxxx popular series, yellow 47-xxxx juvenile series, green (teal) 48-xxxx country series, deep red 49-xxxx classical series, bright red (cerise) 50-xxxx blues/spiritual series, light blue 51-xxxx international series, dark blue 52-xxxx light classics. All colors were soon dropped in favor of black because of production problems. However, yellow and deep red were continued until about 1952. The first 45 rpm record created for sale was "PeeWee the Piccolo" RCA 47-0147 pressed in yellow translucent vinyl at the Sherman Avenue plant, Indianapolis Dec. 7, 1948, R.O. Price, plant manager.

Q1: Which colors of 45 were available as late as 1952 before being discontinued?
A1: yellow and deep red
Q2: PeeWee the Piccolo was what?
A2: The first 45 rpm record created for sale
Q3: What significance does Dec 7/ 1948 hold?
A3: The first 45 rpm record created for sale
Q4: How many colors were 45s available in when first released?
A4: seven colors
Q5: When did RCA release the 45?
A5: March 1949
The normal commercial disc is engraved with two sound-bearing concentric spiral grooves, one on each side, running from the outside edge towards the center. The last part of the spiral meets an earlier part to form a circle. The sound is encoded by fine variations in the edges of the groove that cause a stylus (needle) placed in it to vibrate at acoustic frequencies when the disc is rotated at the correct speed. Generally, the outer and inner parts of the groove bear no intended sound (an exception is Split Enz's Mental Notes).

Q1: In which direction does the groove in a normal disc run?
A1: outside edge towards the center
Q2: How is sound encoded on a commercial disc?
A2: by fine variations
Q3: Does it matter at which speed a disc is spun?
A3: correct speed
Q4: Do all grooves bear data?
A4: no
Towards the center, at the end of the groove, there is another wide-pitched section known as the lead-out. At the very end of this section the groove joins itself to form a complete circle, called the lock groove; when the stylus reaches this point, it circles repeatedly until lifted from the record. On some recordings (for example Sgt. Pepper's Lonely Hearts Club Band by The Beatles, Super Trouper by Abba and Atom Heart Mother by Pink Floyd), the sound continues on the lock groove, which gives a strange repeating effect. Automatic turntables rely on the position or angular velocity of the arm, as it reaches the wider spacing in the groove, to trigger a mechanism that lifts the arm off the record. Precisely because of this mechanism, most automatic turntables are incapable of playing any audio in the lock groove, since they will lift the arm before it reaches that groove.

Q1: What is a 'lead out'?
A1: wide-pitched section
Q2: What is the center where the data joins to complete a circle?
A2: lock groove
Q3: Do turntables play music on lock grooves?
A3: most automatic turntables are incapable
Q4: What do most automatic turn tables do when they meet a lock groove?
A4: lift the arm
Q5: Where do you find a lead out?
A5: Towards the center, at the end of the groove
When auto-changing turntables were commonplace, records were typically pressed with a raised (or ridged) outer edge and a raised label area, allowing records to be stacked onto each other without the delicate grooves coming into contact, reducing the risk of damage. Auto-changers included a mechanism to support a stack of several records above the turntable itself, dropping them one at a time onto the active turntable to be played in order. Many longer sound recordings, such as complete operas, were interleaved across several 10-inch or 12-inch discs for use with auto-changing mechanisms, so that the first disk of a three-disk recording would carry sides 1 and 6 of the program, while the second disk would carry sides 2 and 5, and the third, sides 3 and 4, allowing sides 1, 2, and 3 to be played automatically; then the whole stack reversed to play sides 4, 5, and 6.

Q1: Where were records made with raised label areas?
A1: reducing the risk of damage
Q2: Are longer recordings, as found in operas, made for use with auto-changing systems?
A2: interleaved across several 10-inch or 12-inch discs for use with auto-changing mechanisms
Q3: Do grooves on records touch when stacked?
A3: allowing records to be stacked onto each other without the delicate grooves coming into contact
Q4: Do records touch when in auto changers?
A4: Auto-changers included a mechanism to support a stack
New or "virgin" heavy/heavyweight (180–220 g) vinyl is commonly used for modern audiophile vinyl releases in all genres. Many collectors prefer to have heavyweight vinyl albums, which have been reported to have better sound than normal vinyl because of their higher tolerance against deformation caused by normal play. 180 g vinyl is more expensive to produce only because it uses more vinyl. Manufacturing processes are identical regardless of weight. In fact, pressing lightweight records requires more care. An exception is the propensity of 200 g pressings to be slightly more prone to non-fill, when the vinyl biscuit does not sufficiently fill a deep groove during pressing (percussion or vocal amplitude changes are the usual locations of these artifacts). This flaw causes a grinding or scratching sound at the non-fill point.

Q1: What is the most used material for modern audiophile vinyl releases?
A1: New or "virgin" heavy/heavyweight (180–220 g) vinyl
Q2: What is the material preference of collectors?
A2: heavyweight vinyl
Q3: How does the manufacturing process differ between heavyweight and normal vinyl?
A3: Manufacturing processes are identical
Q4: Would would a non filled area in a vinyl press cause when listening to a record?
A4: grinding or scratching sound
Q5: Which pressing of vinyl require more attention to detail, lightweight or heavyweight?
A5: lightweight records requires more care
The "orange peel" effect on vinyl records is caused by worn molds. Rather than having the proper mirror-like finish, the surface of the record will have a texture that looks like orange peel. This introduces noise into the record, particularly in the lower frequency range. With direct metal mastering (DMM), the master disc is cut on a copper-coated disc, which can also have a minor "orange peel" effect on the disc itself. As this "orange peel" originates in the master rather than being introduced in the pressing stage, there is no ill effect as there is no physical distortion of the groove.

Q1: What is an effect of using worn molds when casting records?
A1: The "orange peel" effect
Q2: What is the expected finish of a vinyl record?
A2: mirror-like
Q3: On what frequencies is an orange peel effect most noticeable?
A3: lower frequency range
Q4: What is the effect on a copy if a master as an orange peel effect?
A4: there is no ill effect
Q5: What material is on a direct metal mastering disc?
A5: copper
Breakage was very common in the shellac era. In the 1934 John O'Hara novel, Appointment in Samarra, the protagonist "broke one of his most favorites, Whiteman's Lady of the Evening ... He wanted to cry but could not." A poignant moment in J. D. Salinger's 1951 novel The Catcher in the Rye occurs after the adolescent protagonist buys a record for his younger sister but drops it and "it broke into pieces ... I damn-near cried, it made me feel so terrible." A sequence where a school teacher's collection of 78 rpm jazz records is smashed by a group of rebellious students is a key moment in the film Blackboard Jungle.

Q1: What was a known issue of using shellac to make records?
A1: Breakage was very common
Q2: In which novel does 'Whiteman's Lady of the Evening" record get broken?
A2: John O'Hara novel, Appointment in Samarra
Q3: In Blackboard Jungle what record breaking mention is made?
A3: teacher's collection of 78 rpm jazz records is smashed
Vinyl records do not break easily, but the soft material is easily scratched. Vinyl readily acquires a static charge, attracting dust that is difficult to remove completely. Dust and scratches cause audio clicks and pops. In extreme cases, they can cause the needle to skip over a series of grooves, or worse yet, cause the needle to skip backwards, creating a "locked groove" that repeats over and over. This is the origin of the phrase "like a broken record" or "like a scratched record", which is often used to describe a person or thing that continually repeats itself. Locked grooves are not uncommon and were even heard occasionally in radio broadcasts.

Q1: What causes clicks and pops on vinyl records?
A1: Dust and scratches
Q2: What is the cause of lock grooves on vinyl records?
A2: Dust and scratches
Q3: Where does the saying "Like a broken record" originate?
A3: locked groove
Q4: How easily do vinyl records break?
A4: Vinyl records do not break easily
Q5: What is a common damage to vinyl records?
A5: easily scratched.
Vinyl records can be warped by heat, improper storage, exposure to sunlight, or manufacturing defects such as excessively tight plastic shrinkwrap on the album cover. A small degree of warp was common, and allowing for it was part of the art of turntable and tonearm design. "wow" (once-per-revolution pitch variation) could result from warp, or from a spindle hole that was not precisely centered. Standard practice for LPs was to place the LP in a paper or plastic inner cover. This, if placed within the outer cardboard cover so that the opening was entirely within the outer cover, was said to reduce ingress of dust onto the record surface. Singles, with rare exceptions, had simple paper covers with no inner cover.

Q1: What causes warping in vinyl records?
A1: heat, improper storage, exposure to sunlight, or manufacturing defects
Q2: What is a cause of once per revolution pitch variation?
A2: warp, or from a spindle hole that was not precisely centered
Q3: What method was used to protect a vinyl record?
A3: place the LP in a paper or plastic inner cover
Q4: What were often found with a paper outter cover and no inner cover?
A4: Singles
Q5: What happens if a vinyl comes with a bit of warp?
A5: A small degree of warp was common,
A further limitation of the gramophone record is that fidelity steadily declines as playback progresses; there is more vinyl per second available for fine reproduction of high frequencies at the large-diameter beginning of the groove than exist at the smaller-diameters close to the end of the side. At the start of a groove on an LP there are 510 mm of vinyl per second traveling past the stylus while the ending of the groove gives 200–210 mm of vinyl per second — less than half the linear resolution. Distortion towards the end of the side is likely to become more apparent as record wear increases.*

Q1: When is distortion most common on a gramophone record?
A1: Distortion towards the end of the side
Q2: What happens as a record wears?
A2: Distortion
Q3: What is a drawback of using gramophones?
A3: fidelity steadily declines as playback progresses
Q4: How much vinyl can be found at the start of an LP?
A4: 510 mm
Q5: Where can you find only 200-210mm of vinyl?
A5: ending of the groove