LP record

From Wikipedia, the free encyclopedia
  (Redirected from Long Play)
Jump to: navigation, search
This article is about vinyl records. For music albums in general, see Album.
"Long play" redirects here. For the video format, see Long play (VCR format). For video game playthroughs, see Longplay (video games).
LP
Capital letters LP in a circle
At top, format logo used on early issues. Below, a typical LP, showing its central spindle hole and label surrounded by the grooved area. Five separate "tracks" are visible, but all are parts of one continuous spiral groove
Media type Audio playback
Encoding Analog groove modulation
Capacity Originally 22 minutes per side, later increased by several minutes, much longer possible with very low signal level
Read mechanism Microgroove stylus (maximum tip radius 0.001 in or 25 µm)
Dimensions 12 in (30 cm), 10 in (25 cm)
Usage Audio storage
Extended from 1948
Extended to Present

The LP (Long Play), or 33 13 rpm microgroove vinyl record, is a format for phonograph (gramophone) records, an analog sound storage medium. Introduced by Columbia Records in 1948, it was soon adopted as a new standard by the entire record industry. Apart from relatively minor refinements and the important later addition of stereophonic sound capability, it has remained the standard format for vinyl albums.

Format advantages[edit]

At the time the LP was introduced, nearly all phonograph records for home use were made of an abrasive (and therefore noisy) shellac compound, employed a much larger groove, and played at approximately 78 revolutions per minute (rpm), limiting the playing time of a 12-inch diameter record to less than five minutes per side. The new product was a 12- or 10-inch (30 or 25 cm) fine-grooved disc made of vinyl and played with a smaller-tipped "microgroove" stylus at a speed of 33 13 rpm. Each side of a 12-inch LP could play for more than 20 minutes. Only the microgroove standard was truly new, as both vinyl and the 33 13 rpm speed had been used for special purposes for many years, as well as in one unsuccessful earlier attempt to introduce a long-playing record for home use.

Although the LP was especially suited to classical music because of its extended continuous playing time, it also allowed a collection of ten or more typical pop music recordings to be put on a single disc. Previously, such collections, as well as longer classical music broken up into several parts, had been sold as sets of 78 rpm records in a specially imprinted "record album" consisting of individual record sleeves bound together in book form. The use of the word "album" persisted for the one-disc LP equivalent.

History[edit]

Soundtrack discs[edit]

Neumann Record Cutting Machine
Neumann Record Cutting Machine
Neumann Record Cutting Machine

The prototype of the LP was the soundtrack disc used by the Vitaphone motion picture sound system, developed by Western Electric and introduced in 1926. For soundtrack purposes, the less than five minutes of playing time of each side of a conventional 12-inch 78 rpm disc was not acceptable. The sound had to play continuously for at least 11 minutes, long enough to accompany a full 1,000-foot (300 m) reel of 35 mm film projected at 24 frames per second. The disc diameter was increased to 16 inches (40 cm) and the speed was reduced to 33 13 revolutions per minute. Unlike their smaller LP descendants, they were made with the same large "standard groove" used by 78s.

Unlike conventional records, the groove started at the inside of the recorded area near the label and proceeded outward toward the edge. Like 78s, early soundtrack discs were pressed in an abrasive shellac compound and played with a single-use steel needle held in a massive electromagnetic pickup with a tracking force of five ounces (1.4 N).

By mid-1931, all motion picture studios were recording on optical soundtracks, but sets of soundtrack discs, mastered by dubbing from the optical tracks and scaled down to 12 inches to cut costs, were made as late as 1936 for distribution to theaters still equipped with disc-only sound projectors.[1]

Radio transcription discs[edit]

Syndicated radio programming was distributed on 78 rpm discs beginning in 1928. The desirability of a longer continuous playing time soon led to the adoption of the Vitaphone soundtrack disc format. 16-inch 33 13 rpm discs playing about 15 minutes per side were used for most of these "electrical transcriptions" beginning about 1930. Transcriptions were variously recorded inside out like soundtrack discs or with an outside start.

Longer pieces recorded live which extended over the course of several discs, pioneered the system of recording odd-numbered sides inside-out and even-numbered sides outside-in so that the fidelity would match when changing sides or discs. Since no changers were present in radio broadcasting, the sides had to be pressed in a hybrid of manual and automatic sequencing, arranged in such a manner that no single disc had to be turned over to play its other half, i.e., instead of a three-disc set having 1–2, 3–4 and 5–6 for manual or 1–6, 2–5 and 3–4 for automatic, broadcast sequences would have 1–4, 2–5 and 3–6.

Some transcriptions were recorded with a vertically modulated "hill and dale" groove, as this was found to allow not only a deeper bass due to the fact that turntable rumble was laterally-modulated in early radio station turntables, but also an extension of the high-end frequency response, neither of which was necessarily a great advantage in practice because of the limitations of AM broadcasting. However, today we can enjoy the benefits of those higher-fidelity recordings, even if the original radio audiences could not.

Initially, transcription discs were pressed only in shellac, but by 1932 pressings in RCA Victor's vinyl-based "Victrolac" were appearing. Other plastics were sometimes used. By the late 1930s, vinyl was standard for nearly all kinds of pressed discs except ordinary commercial 78s, which continued to be made of shellac.

Beginning in the mid-1930s one-off 16-inch 33 13 rpm lacquer discs were used by radio networks to archive recordings of their live broadcasts, and by local stations to delay the broadcast of network programming or to prerecord their own productions. In the late 1940s, magnetic tape recorders were adopted by the networks to prerecord shows or repeat them for airing in different time zones, but 16-inch vinyl pressings continued to be used into the early 1960s for non-network distribution of prerecorded programming. The LP's microgroove standard started to be incorporated in the late 1950s, and in the 1960s the discs were reduced to 12 inches, becoming physically indistinguishable from ordinary LPs. Unless the quantity required was very small, pressed discs were a more economical medium for distributing high-quality audio than tape, so the use of LP-format transcription discs continued into the 1980s. The King Biscuit Flour Hour is a late example.[2]

RCA Victor[edit]

RCA Victor introduced an early version of a long-playing record for home use in September 1931. These "Program Transcription" discs, as Victor called them, played at 33 13 rpm and used a somewhat finer and more closely spaced groove than typical 78s. They were to be played with a special "Chromium Orange" chrome-plated steel needle. The 10-inch discs, mostly used for popular and light classical music, were normally pressed in shellac, but the 12-inch discs, mostly used for "serious" classical music, were normally pressed in Victor's new vinyl-based Victrolac compound, which provided a much quieter playing surface. They could hold up to 15 minutes per side. Beethoven's Fifth Symphony, performed by the Philadelphia Symphony Orchestra under Leopold Stokowski, was the first 12-inch recording issued. The New York Times wrote, "What we were not prepared for was the quality of reproduction ... incomparably fuller."[3][4][5] Unfortunately for Victor, it was downhill from there. Many of the subsequent issues were not new recordings but simply dubs made from existing 78 rpm record sets. The dubs were audibly inferior to the original 78s. Two-speed turntables with the 33 13 rpm speed were included only on expensive high-end machines, which sold in small numbers, and people were not buying many records of any kind at the time. Overall record sales in the US had crashed from a high of 105.6 million records sold in 1921 to 5.5 million in 1933, because of competition from radio and the effects of the Great Depression.[6] Few if any new Program Transcriptions were recorded after 1933 and two-speed turntables soon disappeared from consumer products. Except for a few recordings of background music for funeral parlors, the last of the issued titles had been purged from the company's record catalog by the end of the decade. The failure of the new product left RCA Victor with a low opinion of the prospects for any sort of long-playing record, influencing product development decisions during the coming decade.

Columbia[edit]

CBS Laboratories head research scientist Peter Goldmark led Columbia's team to develop a phonograph record that would hold at least 20 minutes per side.[7] The team included Howard H. Scott, who died September 22, 2012, at the age of 93.[8]

Research began in 1941, was suspended during World War II, and then resumed in 1945.[9] Columbia Records unveiled the LP at a press conference in the Waldorf Astoria on June 18, 1948, in two formats: 10 in (25 cm) in diameter, matching that of 78 rpm singles, and 12 in (30 cm) in diameter.[10] Although they released 100 simultaneously to allow for a purchasing catalogue, the first catalogue number for a 10-inch LP, CL 6001, was a reissue of the Frank Sinatra 78 rpm album set The Voice of Frank Sinatra; the first catalogue number for a 12-inch LP, Columbia Masterworks Set ML 4001, was the Mendelssohn Concerto in E Minor for Violin and Orchestra, Op. 64, played by Nathan Milstein with the Philharmonic-Symphony Orchestra of New York conducted by Bruno Walter. These two albums are therefore the first long-players.

Public reception[edit]

When the LP was introduced in 1948, the 78 was the conventional format for phonograph records. By 1952, 78s still accounted for slightly more than half of the units sold in the United States, and just under half of the dollar sales. The 45, oriented toward the single song, accounted for just over 30% of unit sales and just over 25% of dollar sales. The LP represented not quite 17% of unit sales and just over 26% of dollar sales.[11]

Ten years after their introduction, the share of unit sales for LPs in the US was almost 25%, and of dollar sales 58%. Most of the remainder was taken up by the 45; 78s accounted for only 2% of unit sales and 1% of dollar sales.[6] For this reason, major labels in the United States ceased manufacturing of 78's for popular and classical releases in 1956 with the minor labels following suit, with the final US made 78 being produced in 1959.

Canada and the UK continued production into 1960 and India, the Philippines and South Africa continued to produce 78's up until 1965, with the last holdout, Argentina continuing the practice until 1970.

The LP's popularity ushered in the Album Era of English-language popular music beginning in the 1960s as performers took advantage of the longer playing time to create coherent themes or concept albums. Although the popularity of LPs fell in the late 1970s with the advent of first cassettes and later compact discs, the album survived as a popular format well into the 2000s.

Vinyl LP records have enjoyed an increased resurgence amongst a younger generation in the early 2010s. Vinyl sales in the UK reached 2.8 million in 2012.[12]

Competing formats[edit]

The LP was soon confronted by the 45, a 7-inch (180 mm) fine-grooved vinyl record playing at 45 rpm, introduced by RCA Victor and its parent, the Radio Corporation of America, in 1949. Originally expected to compete with the LP, boxed albums of 45s were issued, as well as EP (Extended Play) 45s, which squeezed two or even three selections onto each side, but the 45 succeeded only in directly replacing the 78 as the format for issuing singles of individual popular songs.

Reel-to-reel magnetic tape recorders posed a new challenge to the LP in the 1950s, but the higher cost of prerecorded tapes was one of several factors that confined tape to a niche market. Cartridge and cassette tapes were more convenient and less expensive than reel-to-reel tapes and became popular for use in automobiles beginning in the mid-1960s. However the LP was not seriously challenged as the primary medium for listening to recorded music at home until the 1970s, when the audio quality of the cassette format was greatly improved by better tape formulations and noise reduction systems. The 1983 world-wide introduction of the digital Compact Disc (CD), which offered a recording that was normally noiseless and not audibly degraded by repeated playing or slight scuffs and scratches, eventually succeeded in toppling the LP from its throne as the initially high prices of CDs and CD players continued to fall.

Along with phonograph records in general, some of which were made of other materials, LPs are now widely referred to simply as "vinyl". From the late 1990s and growing steadily through the 21st century onwards, a renewed interest in vinyl has occurred and the demand for the medium has been on a steady increase yearly in niche markets, particularly among audiophiles, DJs and fans of indie music. Most sales of music are of compact discs or digital file formats because of their generally cheaper prices and wider availability.[13]

The common practice for musicians in recent years has been to release a vinyl disc[citation needed], CD, and digital file at the same time. In most cases[citation needed] if one invests in the slightly higher price of a vinyl disc, they are also given a CD or digital file download code free of charge with the purchase.

Playing time[edit]

When initially introduced, 12-inch LPs played for a maximum of 45 minutes, divided over two sides, with 10-inch versions carrying a maximum of 35 minutes again over two sides.

Owing to marketing attitudes at the time, the 12-inch format was reserved solely for higher-priced classical recordings and Broadway shows. Popular music appeared only on 10-inch records. Executives believed classical music aficionados would leap at the chance to finally hear a Beethoven symphony or a Mozart concerto without having to flip over a seemingly endless series of four-minute-per-side 78s, but popular music fans, used to consuming one song per side at a time, would find the shorter time of the 10-inch LP sufficient. This belief would prove to be erroneous in the end, and by the mid-1950s the 10-inch LP, like its similarly sized 78 rpm record, would lose out in the format wars and be discontinued. Ten-inch records would reappear as mini-albums in the late 1970s and early 1980s in the United States and Australia as a marketing alternative.

Exceptions[edit]

However, in 1952, Columbia Records began to bring out extended-play LPs that played for as long as 52 minutes, or 26 minutes per side.[citation needed] These were used mainly for the original cast albums of some Broadway musicals, such as Kiss Me, Kate and My Fair Lady, or in order to fit an entire play, such as the 1950 production of Don Juan in Hell, onto just two LPs. The 52+ minute playing time remained rare, however, because of mastering limitations, and most LPs continued to be issued with a 30- to 45-minute playing time throughout the lifetime of their production.

An extremely limited number of albums would eventually exceed even the 52-minute limitation, with single albums going to as long as ninety minutes in the case of Arthur Fiedler's 1976 LP 90 Minutes with Arthur Fiedler and the Boston Pops, made by Radio Shack.[14] However, such records had to be cut with much narrower spacing between the grooves, which allowed for a much smaller amount of dynamic range on the records, and meant that playing the record with a worn needle could damage the record. It also resulted in a much quieter sound. Other notably long albums included the UK version of The Rolling Stones' Aftermath, with each side exceeding 26 minutes in length; Genesis' Duke, with each side exceeding 27 minutes; Bob Dylan's 1976 album Desire, with side two being just shy of thirty minutes; Brian Eno's 1975 album Discreet Music, whose A-side exceeded 30 minutes; Miles Davis' 1972 album Get Up with It, totalling 124:15 min over four sides; Todd Rundgren's 1975 album Initiation, totaling 67:32 min over two sides, and his 1973 album A Wizard, A True Star, whose second side reaches almost thirty minutes; La Monte Young's Dream House 78' 17", whose two sides were each just under 40 minutes (the running time of the album is indeed 78:17 min); and André Previn's Previn Plays Gershwin,, with the London Symphony Orchestra, whose sides each exceeded 30 minutes.[15] Single-LP releases of Beethoven's Ninth Symphony contained over 30 minutes on each side, with the third movement split into two parts. The Greenpeace International Record Project released in 1985 also approaches 40 minutes per side over its' two sides. An extremely rare two-disc German pressing restores full sonic clarity and dynamic range lost by the compression to single-disc.

Spoken word and comedy albums, not having a wide range of musical instrumentation to reproduce, can be cut with much narrower spacing between the grooves; for example, The Comic Strip, released by Springtime Records in 1981, has a side A lasting 38:04 min and a side B lasting 31:08 min, for a total of 69:12 min.

In any case, the standard 45-minute playing time of the LP was a significant improvement over that of the previous dominant format, the 78 rpm single, which was generally limited to three to four minutes. At around 14 minutes per side for 10-inch and 23 minutes per side for 12-inch, LPs provided a measured time to enjoy a recording before having to flip discs.

Changers[edit]

Some record turntables, called record changers, could play a stack of records piled on a specially designed spindle and arm arrangement. Because of this, many multiple-record sets were released in what is called "automatic sequence". A two-record set would have Side 1 and Side 4 on one record, and Side 2 and Side 3 on the other, so the first two sides could play in a changer without the listener's intervention, and then they could simply flip the stack over. Larger boxed sets used appropriate automatic sequencing (1–8, 2–7, 3–6, 4–5 for example) to allow for ease of continuous playback, but difficulties if searching for an individual track.

In contrast to compact disc players, very few record players, e.g., laser or selected linear tracking turntables like Sharp RP-107/117,[16] could provide a per-track programmable interface, so the record albums play in the same order every time. As the LP achieved market dominance, musicians and producers began to pay special attention to the flow from song to song, to keep a consistent mood or feel, or to provide thematic continuity, as in concept albums.

Vulnerabilities[edit]

Vinyl records are much more vulnerable to scratches than CDs. On a record, a scratch can cause popping sounds with each revolution when the needle meets the scratch mark. Deeper scratches can cause the needle to jump out of the groove altogether. If the needle jumps ahead to a groove further inward, information gets skipped. And if it jumps outward to the groove it just finished playing, it can repeat in an infinite loop. This particular result of damage spawned the common simile "like a broken record", referring to anything that repeats seemingly endlessly. Additionally, records used in radio stations can suffer cue burn, which is a result of putting the needle on the record and then backing it up approximately a quarter turn so that it will play at the proper speed when the DJ starts the song. When this is done repeatedly, a hissing sound will preface the start of the actual song.

The large surface area of the record, being vinyl which is a material that is susceptible to becoming statically charged, pulls dust and smoke suspended particles out of the air, also causing crackles, pops, and (in the worst cases of contamination) distortion during playback. Records may be cleaned before playing, using record cleaner and/or antistatic record cleaning fluid and anti-static pads.[17]

Since LP discs are delicate, as well as heavy for their size, people are less inclined to lug a stack of them around – for example, when visiting friends or when traveling – than a similar quantity of music compiled onto 90-minute cassettes, compilation-tapes, or today's digital formats.

Groove[edit]

The average LP has about 1,500 feet (460 m or about a third of a mile) of groove on each side. The average tangential needle speed relative to the disc surface is approximately 1 mph, 1.4 km/h or 0.4 m/s. It travels fastest on the outside edge, unlike audio CDs, which change their speed of rotation to provide constant linear velocity (CLV). (By contrast, CDs play from the inner radius outward, the reverse of phonograph records.) This allows the lock-groove effect used by The Beatles on Sgt Pepper's Lonely Hearts Club Band, on which the last track, "A Day in the Life", runs into a continuous loop that will repeat as long as the record player is on.

The empty space before the start of the music has been amplified +15 dB to reveal the pre-echo.

Problems playing this file? See media help.

Thin, closely spaced spiral grooves that allowed for increased playing time on a 33 13 rpm microgroove LP led to a tinny (high frequencies only), faint pre-echo warning of upcoming loud sounds. The cutting stylus unavoidably transferred some of the subsequent groove wall's impulse signal into the previous groove wall. It was discernible by some listeners throughout certain recordings but a quiet passage followed by a loud sound would allow anyone to hear a faint pre-echo of the loud sound occurring 1.8 seconds ahead of time.[18] This problem could also appear as "post"-echo, with a ghost of the sound arriving 1.8 seconds after its main impulse.

The RIAA equalization curve (used since 1954) de-emphasizes the bass notes during recording, allowing closer spacing of record grooves and hence more playing time. On playback, the turntable cartridge pre-amplifier reverses the RIAA curve to flatten out the frequencies again.

Fidelity and formats[edit]

LPs pressed in multicolored vinyl (Sotano Beat: A Todo Color, a various-artists compilation) and clear yellow vinyl - (Rock On Elvis by Tulsa McLean) both from Argentina.

The audio quality of LPs increased greatly over time. The following are some significant advances in the format.

  • stereo sound, 1958
  • helium-cooled cutting heads that could withstand higher levels of high frequencies (Neumann SX68)— (Previously, the cutting engineer had to reduce the HF content of the signal sent to the record cutting head, otherwise the delicate coils could burn out.)
  • Elliptical Stylus (marketed by several manufacturers at the end of the 1960s)
  • cartridges that operate at lower tracking forces (~200 mN), beginning from mid-60s
  • half- and one-third-speed record cutting, which extend the usable bandwidth of the record
  • Matrixed quadraphonic records (SQ, QS, EV-4, UHJ)
  • "discrete" quadraphonic CD4 records, which enabled frequencies of up to 50 kHz to be recorded and played back
  • longer-lasting, antistatic record compounds (e.g.: RCA Dynaflex, Q-540)
  • better stylus tip shapes (Shibata, Van den Hul, MicroLine, etc.)
  • Direct Metal Mastering
  • noise-reduction (CX encoding, DBX encoding), starting from 1973

Early LP recordings were monophonic, but stereo LP records became commercially available in 1958. In the 1970s, quadraphonic sound (four-channel) records became available. These did not achieve the popularity of stereo records, partly because of scarcity of consumer playback equipment, competing and incompatible quad record standards (each of which were compatible with two-channel stereo equipment) and partly because of the lack of quality in quad-remix releases. Quad never escaped the reputation of being a "gimmick". Three-way and quadraphonic recordings, which were favored and championed by artists like Leopold Stokowski and Glenn Gould,[19] are now making a modest comeback, with older masters being turned into multi-channel Super Audio CDs. (However, a fair number of new surround recordings—primarily classical—are being made for SACD and Blu-ray Audio.)

The composition of vinyl (more precisely, a co-polymer of vinyl chloride acetate) used to press records has varied considerably over the years. Virgin vinyl is preferred, but during the 1970s energy crisis, it became commonplace to use recycled vinyl—melted unsold records with all of the impurities. Sound quality suffered, with increased ticks, pops and other surface noises.[citation needed] Other experiments included reducing the thickness of LPs, leading to warping and increased susceptibility to damage. Using a bead of 130 grams of vinyl had been the standard, but some labels experimented with as little as 90 grams per LP.[citation needed] Today, high fidelity pressings follow the Japanese standard of 160, 180 or 200 grams.[citation needed]

Besides the standard black vinyl, specialty records are also pressed on different colors of PVC or special "picture discs" with a card picture sandwiched between two clear sides. Records in different novelty shapes are also produced.

Use by disc jockeys[edit]

Disc jockeys (or DJs) in clubs still rely heavily on vinyl records, as cuing tracks from cassette tapes is too slow and CDs did not allow creative playback options until quite recently. The term "DJ", which had always meant a person who played various pieces of music on the radio (originally 78s, then 45s, then tape cartridges and reels; now cuts from CDs or tracks on a computer) – a play on the horse-racing term "jockey" – has also come to encompass all kinds of skills in "scratching" (record playback manipulation) and mixing dance music, rapping over the music or even playing musical instruments, but the original dance club (non-radio) definition was simply somebody who played records, alternating between two turntables. The skill came in subtly matching beats or instruments from one song to the next, providing a consistent dance tempo. DJs also made occasional announcements and chatted with patrons to take requests while songs were actually playing, similar to what radio disc jockeys have been doing since the 1940s.

See also[edit]

References[edit]

  1. ^ Frequently Asked Questions "Frequently Asked Questions". The Vitaphone Project. Retrieved 2011-08-12. 
  2. ^ "Rand's Esoteric OTR: Types of transcriptions and radio recordings". Randsesotericotr.podbean.com. Retrieved August 12, 2011. 
  3. ^ "Phonograph Disks Run for Half-Hour". The New York Times. September 18, 1931. p. 48. Retrieved November 25, 2012. 
  4. ^ Compton Pakenham (September 20, 1931). "Newly Recorded Music". The New York Times. p. X10. 
  5. ^ "Not So New", The Billboard, June 5, 1948, p. 17.
  6. ^ a b Robert Shelton (March 16, 1958). "Happy Tunes on Cash Registers". The New York Times. p. XX14. 
  7. ^ Goldmark, Peter. Maverick inventor; My Turbulent Years at CBS. New York: Saturday Review Press, 1973.
  8. ^ Ben Sisario (October 6, 2012). "Howard H. Scott, a Developer of the LP, Dies at 92". The New York Times. Retrieved October 8, 2012. "Howard H. Scott, who was part of the team at Columbia Records that introduced the long-playing vinyl record in 1948 before going on to produce albums with the New York Philharmonic, Glenn Gould, Isaac Stern and many other giants of classical music, died on Sept. 22 in Reading, Pa. He was 92. ..." 
  9. ^ "Columbia Diskery, CBS Show Microgroove Platters to Press; Tell How It Began", Billboard, June 26, 1948, p. 3.
  10. ^ Marmorstein, Gary. The Label: The Story of Columbia Records. New York: Thunder's Mouth Press; p. 165.
  11. ^ "78 Speed On Way Out; LP-45 Trend Gaining", The Billboard, August 2, 1952, p. 47.
  12. ^ 1 What a record! The UK album chart reaches its 1,000th No1... and counting, Express, Adrian Lee, November 26, 2013
  13. ^ McGeehan, Patrick (December 7, 2009). "Vinyl Records and Turntables Are Gaining Sales". The New York Times. Retrieved May 11, 2010. 
  14. ^ 90 Minutes with Arthur Fiedler and the Boston Pops, Radio Shack/Realistic Cat. No. 50-2040, 1976 (copyright 1974, 1976, Polydor Records)
  15. ^ London Symphony Orchestra, Previn Plays Gershwin, André Previn, pianist and conductor (featuring Rhapsody in Blue, An American in Paris and the Concerto in F for Piano and Orchestra), Angel SFO 36810, circa 1979
  16. ^ "Vinyl Engine page for the Sharp RP-107".
  17. ^ [1][dead link]
  18. ^ Audacity Team Forum: Pre-echo when recording vinyl record
  19. ^ Gould Radio Portrait of Stokowski for CBC

External links[edit]