Leopold Stokowski, Dr. Harvey Fletcher and the Bell Laboratories Experimental Recordings
Leopold Stokowski with Dr. Harvey Fletcher
Stokowski, The Philadelphia Orchestra and the Bell Laboratories Experimental Recordings
Stokowski's Interest in Broadcasting Technology
In 1929, the Philadelphia Orchestra began live broadcasts of concerts from the Academy of Music via the NBC radio network. Arthur Judson, the famous manager had been urging Stokowski to broadcast for some time, but Stokowski was dissatisfied by the sound of these early broadcasts.
About this same time, Stokowski approached Harvey Fletcher at the Bell Laboratories seeking ways to improve this transmission.
Harvey Fletcher and the Bell Laboratories Research in Recording Technology
Harvey Fletcher was a brilliant physicist who had worked at the University of Chicago with Nobel Prize winner Robert A. Millikan (1868-1953). Millikan was famous for his measurement of the charge of the electron in 1910, and for his work on the photoelectric effect (confirming Einstein's theory of the photon theory of light). Millikan then went on to serve as president of Caltech from 1921 to 1945. Fletcher received his Ph.D. from the University of Chicago summa cum laude, working with Millikan on determining the value of the charge of the electron. Fletcher later became Director of Research at Bell Laboratories, where he oversaw three decades of research and improvement in sound, hearing, transmission, and reproduction.
Stokowski, Harvey Fletcher and Robert Millikan in 1936 13
At Bell Laboratories, Fletcher oversaw research in this area by Joseph P. Maxfield, Henry C. Harrison, K. P. Secord, Rogers H. Galt 12, Harold Black (who invented the negative feedback amplifier in 1927), Arthur C. Keller and others.
Harrison and Maxfield made a number of developments which, together allowed the creation of an electrical sound recording system. One of these was the development of a matched-impedance electronic system, with a carbon microphone, linked to a tube or valve amplifier, driving a moving magnet (called also a 'moving armature') cutting head to scribe the sound in the wax master.
This matched-impedance electrical recording system had a recording bandwidth from 50 Hertz to 6,000 Hertz, beyond which its sensitivity declined. This wider bandwidth added another octave of sound reproduction, compared with the acoustic process, along with the reduced harmonic distortion and a generally more realistic sound image.
Harvey Fletcher, K. P. Secord, and Rogers H. Galt at the Bell Laboratories
In a 1981 BBC Radio 3 interview, Arthur C. Keller, who worked for Henry Harrison, told of his early sound and recording efforts and those of his colleagues in the 1920s and 1930s at the Bell Laboratories. They were working initially on long line transmission, and later on high fidelity and binaural or stereophonic recording. Keller spoke of Bell Laboratories work with Stokowski and the Philadelphia Orchestra to achieve high quality recordings and broadcast transmission from the Academy of Music in Philadelphia in 1930 and 1931.
1930 Advertisement for the Sunday Stokowski - Philadelphia Orchestra broadcast
1931 - Bell Laboratories Experimental Recordings of Stokowski and the Philadelphia Orchestra
In April, 1931, Bell Labs began recording Stokowski and the Philadelphia Orchestra in the Academy of Music, using new equipment installed in the basement, with Stokowski's permission. This equipment, did not use the conventional lateral cutting heads used for contemporary 78 rpm disks. Keller’s disk cutting equipment used a vertical cut (“hill and dale”) recording method, using a magnetic moving coil pickup fitted with a sapphire stylus cutting the wax master.
The vertical cutting device improved stylus tracking and thereby reduced harmonic distortion. It also helped to expand the dynamic range of the recording.
Moving coil microphones, capable of frequencies above 10,000 Hz, developed by Bell Laboratories were used in both the monophonic and 'binaural' recordings. Reportedly, more than 100 78 RPM sides were cut in the Academy of Music during the 1931 - 1932 Philadelphia Orchestra season.
Bell Labs had also earlier determined that surface noise on 78 wax recording masters (called the “matrix”) was caused by the graphite which was deposited on the wax surface during the manufacturing process. In the web page Eldridge Johnson, Victor, and the Development of Acoustic Recording, you can read that first lead powder, and later copper powder was brushed on the wax master to make it conductive for electroplating. Later, graphite was adopted. The graphite allowed the surface of the master to become conductive, so it could be electroplated, preliminary to the later steps in producing record “stampers”. As described in ' Eldridge Johnson Develops Electroplating of the Wax Master ', this electroplating technique was the key to permitting creation of multiple versions of "masters" , used in the mass production of records.
Arthur Keller and A.G. Russell devised the approach of processing the wax masters by means of gold sputtering, in a vacuum chamber, which laid down a one molecule thickness of gold onto surface of the wax. This layer allowed them to electroplate a copper layer onto the gold, thus bypassing the need for graphite.
Pressings of the recordings were then made using cellulose acetate disks, rather than the typical noisy shellac material of the 78 rpm era.
In December, 1931, the first electrical recordings with this improved process were made and the experiments continued throughout the 1931-32 concert season. The audio spectrum was extended first to 9,000 Hz and then to 10,000 Hz, giving for the first time good fidelity in the overtones and treble range of instruments.
Bell Laboratories asked Arthur Keller to come out of retirement in 1979 to catalogue, and transcribe some of the gold sputtered disks still in storage. Keller identified Stokowski - Philadelphia recordings from among 600 metal masters at the Bell Laboratories in Murray Hill, New Jersey4. Of these, more than 100 were preserved by transcription.
With the typically excellent and energetic transcriptions by Ward Marston, many of the metal masters were saved, cataloged, and transcribed, including some of the stereo items. Based on Ward Marston and Arthur Keller's work, Bell Telephone issued two commemorative albums with some of these transcriptions in 1981. As far as I have been able to determine, all of the CDs which circulate with some of this material come from the Bell LP disks compiled by Arthur Keller and Ward Marston. We are indebted to them for this work.
The 1981 Bell Laboratories LP of 1931 and 1932 Philadelphia Performances
The Roman Carnival Overture was recorded December 5, 1931 in the Academy of Music, without the knowledge of the orchestra members, who did not notice, since radio microphones were routinely strung from the Academy of Music ceiling. Keller had installed his recording equipment in the basement below the orchestra stage. Stokowski later said, when he heard the Roman Carnival recording at the Bell Laboratories in New York City that it was the best quality recording he had ever heard.
Keller said that their recorded response in the Roman Carnival extended to 13,000 Hz, the highest to that point achieved by Bell Laboratories5. You may hear this mono recording by clicking on the link, below.
Click here to listen to the December 5, 1931 recording of the Roman Carnival Overture
In March, 1932, Keller recorded the Philadelphia Orchestra for the first time in “binaural” or stereo sound, by connecting two different microphones each to its own cutting stylus, with each moving magnet cutting stylus in its own arm, each parallel to the other, but one recording from the outer edge of the wax disk (as was normal), and the other beginning half way into the disk, so that each would cut half of the disk with a right and a left channel. On March 12, 1932 Stokowski recorded the Scriabin "Poem of Fire" in this format. This recording is the earliest surviving example of stereophonic recording.
Alan Blumlein and the development of Electrical and Stereophonic Recording
Another early pioneer of stereophonic recording was done at EMI in Hayes, Middlesex, UK by the brilliant young scientist Alan Blumlein.
Alan Blumlein in the 1930s
Blumlein had joined the Columbia Gramophone Company in March, 1929 reporting to another great man and engineer, Isaac Schoenberg (in 1962, Sir Isaac Schoenberg) who had become General Manager of Columbia in 1928. Schoenberg had previously been General Manager of the Marconi Wireless and Telegraph Company.
Sir Isaac Schoenberg
Schoenberg, who had emigrated from Russia to England in 1914, hired Blumlein to join him at Columbia Gramophone. He assigned Blumlein the job of inventing a new electrical recording process not dependent on the Bell Labs/Western Electric Westrex process. The UK Columbia company had purchased the failing US Columbia company in 1924, and had then licensed the Westrex process from Western Electric (who initial licensed only US firms) in late 1924, somewhat before the Victor Talking Machine Company. This may have influenced Victor also to license the Westrex process.
In 1929 and 1930, Blumlein developed a superior disk cutting technology, using moving coil cutting heads, rather than the moving magnet technology of the Westrex process. He also developed a moving coil microphone at about this time. Interestingly E.C. Wente of Bell Laboratories also developed a moving coil microphone in 1928, which was patented (1,766,473) in 19319. Wente's Western Electric Model 618A of 1931 was nearly flat in response from 30 to15,000 Hertz, and its low impedance (30 Ohm) allowed long cables without significant signal loss10.
E. C. Wente Western Electric Moving Coil Microphone Model 618A of 1931
These inventions by Blumlein eliminated the royalties paid to Western Electric on each disk using the 'Westrex' process. These inventions are particularly impressive, given that Blumlein was working for the most part alone, with some assistants, whereas E. C. Wente, Joseph P. Maxfield, Henry C. Harrison were working as part of a large Bell Laboratories team. Blumlein, as well as saving EMI the Westrex royalty payment, developed a moving coil cutting head which was superior to the Westrex system, since it reduced distortion and increased frequency response, and tended to be more linear in frequency response during the critical step of cutting the wax master.
In 1931, in part because of the effects of the great depression, the Gramophone Company (HMV) merged with Blumlein's employer, Columbia Gramophone Company (Columbia) to form Electric and Musical Industries: EMI. In November, 1931, EMI also built the famous new recording studios at 3 Abbey Road, in St. John's Wood, London, at that time, the largest recording studios in the world.
In 1933, using the stereophonic developments which Blumlein patented (patent issued in June 14, 1933), EMI cut a stereophonic disk with two channels in one groove, cut 90 degrees apart. Blumlein's first recording apparatus is described by A. J. Lodge of EMI Labs, in R. W. Burn's excellent 'The Life and Times of A D Blumlein'. "...The stereo wax cutter survives as well. It was made from two Western Electric moving-armature units coupled to a single stylus by a lightweight lever system, so that one unit moved the stylus vertically, and the other horizontally. The first calibration of the recorder is believed to have been on 12th July 1933. Bandwidth is reported to have been about 4kHz.......It was with this set-up that the well-known 'walking' and 'talking' records, the first complex-cut stereo records ever, were made some time before 16th December 1933......The signals feeding the two cutters were sum, for the lateral cutter, and difference for the vertical... "
This technique was similar to Arthur Keller's patent, but slightly different. Keller's patent, written in 1931 and 1932, but not submitted until 1936, taught having both channels cut 45 degrees from vertical, and 90 degrees from each other.
So, Blumlein's pioneering stereo work resulted in the first pressing of a stereophonic disk with two channels in one groove. It is interesting that Keller had conceived of this 45 degree rotation so that each channel would have potentially similar reproduction, since he found that cutting purely vertical and horizontal groves having differences in reproduction. In contrast, the first EMI stereo disk had one channel cut horizontally, and the other vertically, like the old 'hill and dale' cutting method of companies such as Pathé, although Blumlein did later work on 45 degree oriented groves.
The two channels in one groove, and the 45 degree orientation seems to have been forgotten until the period 1954 - 1958, when Westrex of Hollywood, California. Westrex was sold to Litton Industries, and which prospered for a time in stereo and Hollywood sound systems. Westrex developed the stereo Westrex groove design, reinventing the 45 degree orientation (see The Westrex Stereo Disk System).
Arthur Keller and the Transcription of the Bell Labs Recordings
So, these pioneering Bell Labs - Stokowski recordings of March 12, 1932 are the oldest stereo recordings we have. You may hear two stereo tracks transcribed in 1980 by Arthur Keller from the old metal masters at the Bell Labs, of the "Poem of Fire" by Alexander Scriabin (1874 - 1915), below.
Alexander Scriabin in about 1900
Keller later thought of the idea of recording the two channels of a stereo recording in one record groove each at 45 degrees from vertical and 90 degrees from each other. Keller was awarded US patent 2,114,471 for this method, which was re-invented in the 1950 for the Westrex stereo recording process.
The 1931 and 1932 experimental stereophonic recordings were made employing two cutting styli making two separate grooves in the wax master, one starting at the disk edge (as was normal), and the other starting at the middle of the wax master. 125 of these Bell Labs/Philadelphia Orchestra test recordings of 1931 and 1932 have been preserved. Some are stereophonic and others are extended range monophonic. The March, 1932 stereophonic recordings are the oldest stereophonic recordings to have survived.
In 1933, EMI, using the stereophonic developments patented by the brilliant Alan Blumlein, cut a stereophonic disk with two channels in one groove, cut 90 degrees apart, as with Arthur Keller's patent. However, Keller's patent taught having both channels cut 45 degrees from vertical, whereas the EMI disk had one channel cut horizontally, and the other vertically, like the old 'hill and dale' cutting method of companies such as Pathé. Thanks to restoration work supervised by Arthur Keller himself and funded by Bell Labs, a limited edition album of some of these 1931 and 1932 masters was released in 1980. In restoring these historic recordings, Keller did not use the original cellulose acetate pressings, but rather worked directly from the master “mother” disks, which are essentially the negative images of the disk pressing. The “negative” grooves are raised up from the master's surface, and these would have formed the record grooves if pressed into the record material.
For this reason, Keller used a stylus shaped like a fork, which would ride on the top of the raised, negative grooves, with the turntable revolving “backwards” since the disk is a negative of the finished 78 rpm disk.
1933 Long Distance Concert - Philadelphia to Washington
On April 27, 1933 Bell Labs, Fletcher and Keller also arranged long distance transmission of high quality stereophonic sound across telephone long lines capable of sound transmission up to 10,000 Hz. It is interesting to note that what must have been the first telephone transmission of music also involved the Academy of Music. As cited in Music in Philadelphia, "...Mr. Bocovitz, the renowned pianist, played...Home Sweet Home...and other airs in New York. The audience heard this program via telephone at the Academy of Music in Philadelphia." 11
A concert of the Philadelphia Orchestra at the Academy of Music, sponsored by AT&T was captured by three microphones spaced across the front of the orchestra and transmitted via three long lines to Constitution Hall in Washington, D.C. where three amplified loudspeakers reproduced the orchestra sound. The orchestra was conducted by Alexander Smallens, assistant conductor of the Philadelphia Orchestra, with Stokowski controlling sound balance.
S tokowski at the controls in the 1933 Washington DC stereo broadcastwith Harvey Fletcher observing
The Washington DC broadcast concert was advertised as demonstrating “…the recent advances in high-quality telephonic transmission and reproduction of music…" On April 9 and April 10, 1940, Harvey Fletcher and Stokowski arranged another demonstration of stereo sound in Carnegie Hall with music recorded onto a three channel system using sound recorded optically on film with a frequency range of 30 Hz to 15,000 Hz.
Sources:
4 page 805
Journal of the Audio Engineering Society. Volume
31 no 10. October, 1983.
5
Fox, Barry “A Hundred Years of Stereo”, New Scientist December 1981
Alexander, Robert Charles. The Inventor of Stereo: The Life and Works of Alan Dower Blumlein Focal Press 2000 ISBN 0240516281
Fagen, M.D., ed. A History of Engineering and Science in the Bell System: The Early Years (1875-1925). New York: Bell Telephone Laboratories, 1975
Arthur Keller: BBC Interviews, broadcast 1981
Utah History http://historytogo.utah.gov/people/utahns_of_achievement/harveyfletcher.html
http://www.bell-labs.com/about/history/innovations_in_sound.html
9 Bell Laboratories Patents
10 Schoenherr, Steven Recording Technology History July 6, 2005 http://history.sandiego.edu/GEN/recording/notes.html
11 page 160. Gerson, Robert A. Music in Philadelphia Theodore Presser Co. Philadelphia. 1940.
12 Thanks to Christine Rankovic, Ph. D. for this information
on Rogers Harrison Galt.
13 Photograph from Harvey Fletcher "My work with Millikan on the oil-drop experiment" Physics Today. American Institute of Physics, College Park, Maryland, USA June 1982. Again, thanks to Christine Rankovic, Ph. D. for this material
If you have any comments or questions about this Leopold Stokowski site, please e-mail me (Larry Huffman) at e-mail address: leopold.stokowski@gmail.com
L'Héritage de Stokowski - Accueil français 1917 - Premiers enregistrements acoustique de Stokowski - Orchestre de Philadelphie 1917 - 1919 autres enregistrements acoustique Stokowski - Orchestre de Philadelphie 1920 - 1921 autres enregistrements acoustique Stokowski - Orchestre de Philadelphie 1922 - 1924 autres enregistrements acoustique Stokowski - Orchestre de Philadelphie 1919 - 1924 enregistrements acoustique Russe Stokowski - Orchestre de Philadelphie 1920 - 1924 enregistrements acoustique français - Stokowski - Orchestre de Philadelphie 1921 -1924 enregistrements acoustique Tchaïkovski - Stokowski - Orchestre de Philadelphie 1921 - 1924 enregistrements acoustique Wagner - Stokowski - Orchestre de Philadelphie 1924 enregistrements acoustique Rachmaninov - Stokowski - Orchestre de Philadelphie
Développement de l'enregistrement électrique Permis d'exploitation du système Westrex donné à Victor et Columbia 1925 Premier enregistrement électrique Stokowski - Orchestre de Philadelphie 1925 autres enregistrements électriques Stokowski - Orchestre de Philadelphie 1926 enregistrements électriques Stokowski - Orchestre de Philadelphie 1927 enregistrements électriques Stokowski - Orchestre de Philadelphie Encore des enregistrements 1927 électriques Stokowski - Orchestre de Philadelphie 1928 enregistrements électriques Stokowski - Orchestre de Philadelphie 1929 enregistrements électriques Stokowski - Orchestre de Philadelphie 1930 enregistrements électriques Stokowski - Orchestre de Philadelphie 1931 enregistrements électriques Stokowski - Orchestre de Philadelphie 1932 enregistrements électriques Stokowski - Orchestre de Philadelphie 1933 enregistrements électriques Stokowski - Orchestre de Philadelphie 1934 enregistrements électriques Stokowski - Orchestre de Philadelphie Encore des enregistrements 1934 électriques Stokowski - Orchestre de Philadelphie 1935 enregistrements électriques Stokowski - Orchestre de Philadelphie 1936 enregistrements électriques Stokowski - Orchestre de Philadelphie 1937 enregistrements électriques Stokowski - Orchestre de Philadelphie 1939-1940 enregistrements électriques Stokowski - Orchestre de Philadelphie
D'autres documents sur Stokowski et l'Orchestre de Philadelphie Camden église studio - Victor Talking Machine studio d'enregistrement Leopold Stokowski - Orchestre de Philadelphie Enregistrement à l'Académie de musique de Philadelphie Interviews avec Leopold Stokowski Leopold Stokowski Orchestrations Leopold Stokowski, Harvey Fletcher et les laboratoires Bell expérimental enregistrements Maîtres de restauration moderne de disques historique CDs de Stokowski et l'Orchestre de Philadelphie Leopold Stokowski Discographies chronologique Leopold Stokowski Discographie chronologique - enregistrements acoustique Leopold Stokowski Discographie chronologique - enregistrements électriques Leopold Stokowski - Orchestre de Philadelphie bibliographie, des sources et crédits
L'Orchestre symphonique de Boston - musiciens principaux L'Orchestre symphonique de Chicago - musiciens principaux L'Orchestre de Cleveland - musiciens principaux L'Orchestre du Metropolitan Opera de New York - musiciens principaux L'Orchestre philharmonique de New York - musiciens principaux L'Orchestre de Philadelphie - musiciens principaux L'Orchestre symphonique Russe de New York - musiciens principaux L'Orchestre symphonique de San Francisco - musiciens principaux L'Orchestre symphonique de St. Louis - musiciens principaux
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