In 1929, the Philadelphia Orchestra began live broadcasts of concerts
from the Academy of Music, Philadelphia via the NBC radio network.
Arthur Judson, the famous orchestra 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 Dr. Harvey Fletcher (1884-1981)
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 studied and worked at the
University of Chicago, where he aided Dr. Robert A. Millikan (1868-1953) in
his reseach. Millikan was famous for his measurement of the charge of
the electron (aided by Harvey Fletcher), and for his work on the
photoelectric effect (confirming Einstein's theory of the photon theory of
light). Millikan was awarded the Nobel Prize in Physics in 1923 for
his measurement of the electron charge, one of the fundamental physical
constants in partical physics. Millikan then went on
to serve as president of the California Institute of Technology 1921-1945.
Harvey Fletcher received his Ph.D. in Physics from the University of Chicago
in 1911 summa cum laude. Harvey Fletcher
later became Director of Research at Bell Laboratories, where he oversaw three
decades of research and improvement in sound, hearing, transmission, and sound
Stokowski, Harvey Fletcher and Robert Millikan in 1936 13
At Bell Laboratories, Fletcher oversaw research by (among others) Joseph P.
Maxfield, Henry C. Harrison, Edward Christopher 'E.C.' Wente,
K. P. Secord, Rogers H. Galt, Harold Black (who invented the negative
feedback amplifier in 1927) 12, Arthur C. Keller and
others working on amplification, electronic sound
transmission, recording and reproduction.
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. The new electrical recording system dramatically
improved on the acoustic recording system, invented by Thomas Edison and
gradually improved until it could record approximately from 250 Hertz to
about 2,400 Hertz (sometimes). This new, wider bandwidth of the
electrical recording system added another octave of sound reproduction,
compared with the acoustic process, and greatly reduced the
harmonic distortion of the acoustic process, and produced a generally more
realistic sound image. You can read about these developments in
The Development of Electrical Recording
, elsewhere on this site.
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 and the Bell Lab's 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 with better sound fidelity, and
later on high fidelity and binaural or stereophonic recording. In the
interview which you can listen to by clicking below, Keller spoke of Bell
Laboratories work with Stokowski and the Philadelphia Orchestra in test recordings
to achieve high quality recordings and broadcast transmissions from the Academy
of Music in Philadelphia in 1930 and 1931.
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 capturing frequencies above 10,000 Hz,
developed by Bell Laboratories were used in both the monophonic and
"binaural (or stereophonic) recordings. Reportedly, more
than one thousand 78 RPM sides were cut in the Academy of Music during the
1931 and 1932 experimental Philadelphia Orchestra recordings.
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 conductive layer allowed them to electroplate a
copper layer onto the gold surface, thus bypassing the need for
the conductive graphite surface. This eliminated the surface
noise resulting from the graphite on the surface of the recording.
Pressings of the recordings from these quiet masters were then made using
cellulose acetate disks, rather than the typical noisy shellac material
of the usual 78 rpm disks of that era.
In December, 1931, the first electrical recordings with this improved
process were made and the experiments continued throughout the 1931-1932
concert season. The audio spectrum was extended first to 9,000 Hertz
and then to 10,000 Hertz, 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 assist in transcribing 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, done by
the legendary remastering engineer Ward Marston. I should add
that Arthur Keller in his interviews does not give (in my opinion)
the proper recognition of the contributions of Ward Marston in restoring
and therefore making available these historic, and wonderful recordings.
Ward Marston, Arthur Keller and their associates were able to save
many of the old metal masters. These masters were then cataloged
and transcribed, including some of the stereo masters. Based
on Ward Marston and Arthur Keller's work, Bell Telephone issued
two commemorative albums with some of these transcriptions in 1979
and 1980, Bell Telephone BTL-7901 and BTL-8001. As far as I have
been able to determine, all of the CDs and other media which circulate with some
of this material come from these Bell LP disks compiled by Arthur
Keller and Ward Marston, whatever these 'knock-off' CDs
may claim (or leave unsaid). The Bell Laboratories
disks are the only sources of this pioneering recordings (at least so far)
and we are indebted to Bell Laboratories of 1979-1981, and to Keller and
Marston for the surperb examples of these important early sound experiments.
The 1981 Bell Laboratories LP of 1931 and 1932 Philadelphia Performances
1931 Roman Carnival Overture
The Berlioz Roman Carnival Overture was recorded December 5, 1931
in the Academy of Music, without the knowledge of the orchestra members.
The musicians likely did not notice anything unusual, since radio microphones
were routinely hanging from the Academy of Music ceiling. Arthur Keller
had installed his recording equipment in the basement below the orchestra stage,
where the Victor Talking Machine Company electrical recording equipment had also
been installed in 1926. 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.
Arthur Keller said that their recorded response in the Roman Carnival
extended to 13,000 Hertz, the highest frequency response achieve up until that
time by Bell Laboratories5. The restored recording in the
links, below, were done by the mastering and restoration engineer
, from the original Bell Labs LP disks and they are both excellent and subtle
restorations. You can contact him at Marcos Abreu - Audio mastering
and restoration services, email address:
Thanks Marcos ! Listen to Marcos' results by clicking
on the link, below.
As well as developing higher-fidelity sound reproduction with expanded
frequency range and reduced harmonic distortion, Bell Laboratories
also developed and used stereophonic recording technology for the
first time. In March, 1932, Bell Laboratories recorded the
Philadelphia Orchestra in "binaural" or stereophonic
sound, by connecting two different microphones each to its own
cutting stylus, with each moving magnet cutting stylus. The
two cutting styli were each in its own arm, 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. As a result,
each stylus would cut half of the 78 RPM disk with a record groove
containing a right or a left audio channel. Playback was the
reverse process, using two playback styli.
Using this stereophonic equipment, the Bell Laboratories engineers
recorded Stokowski and the Philadelphia Orchestra in a Russian program
on March 12, 1932 in the Academy of Music. They recorded
the Poem of Fire opus 60 by Alexander Scriabin (1874 - 1915)
and the Mussorgsky-Ravel Pictures at an Exhibition in this
format. These recordings are the earliest surviving examples
of stereophonic recording.
You may hear two stereo tracks of the Poem of Fire transcribed
from the old metal masters by clicking on the links below.
March 1932 Modest Mussorgsky - ' Tableaux d'une Exposition' - 'Pictures at an Exhibition'.
On March 12, 1932, the Bell Laboratories experimental equipment recorded
Stokowski and the Philadelphia Orchestra performing Maurice Ravel's orchestration
of Tableaux d'une Exposition in both their high fidelity and
stereophonic recording technology.
The original composition was written by Mussorgsky in 1874
and were his musical impressions of 10 (or perhaps 11) pictures, or
tableaux by Mussorgsky's friend Viktor Hartmann (1834–1873), shown at
a retrospective exhibition of Hartmann's works. Hartmann
had died unexpectedly of an aneurysm the year before Mussorgsky
wrote 'Pictures at an Exhibition'. Hartmann's death is said
to have made a deep impression on Mussorgsky, and Mussorgsky (who
also died young 1839-1881) later recounted that he composed
these piano pieces in only six weeks.
Serge Koussevitzky commissioned Maurice Ravel to orchestrate
the Tableaux d'une Exposition. After Koussevitzky's
exclusive period of performance of the transcription ended in
the late 1920s, Stokowski performed the Ravel transcription a
number of times.
However, ass you may read elsewhere in this www.stokowski.org site, Stokowski
was not totally satisfied with Ravel's orchestration. Stokowski did
not commercially record the full Ravel orchestration, but rather made his
own orchestration. You can read about Stokowski's efforts and also
listen to the Stokowski transcription by clickin on the link to the page
1939 - Mussorgsky - Pictures at an Exhibition - Stokowski Orchestration.
Stokowski's score for 'Tableaux d'une Exposition' 1939
The March 12, 1932 performances Tableaux d'une Exposition resulted in
four excerpts from the work which Ward Marston was able to expertly
assemble together to provide these satisfying, extended excerpts.
These excerpts have been restored from the Bell Laboratories LP recording
by the mastering and restoration engineer
, in an excellent and subtle restoration. (You can contact him at
Marcos Abreu - Audio mastering and restoration services, email address:
Listen to these excerpts by clicking on the links, below.
The excerpts include:
Those who know Tableaux d'une Exposition well will notice that both
Les Tuileries, the third 'picture' and Limoges, le marché, the
seventh 'picture' are not included in these excerpts. This is because
Stokowski did not perform them. He seems to have formed the theory that
these two pictures were not really intended by Mussorgsky, but rather inserted
by Ravel from other music. Stokowski also found Ravel's orchestration in
these two cases too French, and not sufficiently dark and Slavic.
So, he did not include them when he performanced the Ravel orchestration.
He also did not include these tableaux at all in his own later
orchestration of Tableaux d'une Exposition.
April 29, 30, 1932 Performances of Music from Wagner's Ring des
On Friday April 29 and Saturday April 30, 1932, Stokowski and the
Philadelphia Orchestra gave two performances of music from Wagner's
Ring des Nibelungen. Bell Laboratories recorded excerpts of
these concerts in what are likely the best Wagner performances Stokowski
made with the Philadelphia Orchestra during the 1930s. These excerpts
were from from Die Walküre, Siegfried, and
Ward Marston in his notes to the Bell Laboratories LP writes:
of the Saturday performance were recorded in two-band stereo, and in every case
these stereo excerpts have been incorporated here - however fleeting in
duration they may be. Throughout the first side of this record [note: the
Die Walküre excerpts and the Siegfried Forest Murmurs] the listener will
be aware of a change in sound from monaural into stereo and back again. This
approach was adopted to maintain musical continuity while preserving what
stereophonic excerpts survive...".
Die Walküre: Wotan's Farewell and Magic Fire Music
As Ward Marston's notes remark, this famous excerpt from Die Walküre:
Wotan's Farewell and Magic Fire Music, recorded during concerts of
April 29 and 30, 1932 are partially in stereo. This dramatic scene
from the finale of the opera, Act 3, represents the confrontation between
Wotan and his daughter Brünnhilde, when he condemns her to mortality and
to a magic sleep. However, he relents and surrounds her with a magic
fire, so that only the bravest hero (here the Siegfried motif is heard in
the music) will penetrate the ring of fire to save Brünnhilde.
This performance is poignant and magical, as of course it should be.
The sound, amazing for this era, and of a 'live' performance is yet more striking.
Ward Marston in his notes for the Bell LP states:
"...In this recording, a 17 second gap in the Magic Fire Music
has been filled from a 1939 recording, with the kind permission of RCA
Records, and there is a 90 second gap near the beginning of Wotan's
Farewell, which was impossible to fill from any other
Concluding the first half of the April 29 and 30, 1932 all
Wagner concert was the Siegfried Forest Murmurs scene from
Act 2 of Siegfried when Siegfried is in the woods in front
of Fafner's cave. After slaying the dragon, Siegfried's hand
touches the dragon's blood, allowing him to understand the song of
the birds, who tell him of Brünnhilde. This wonderfully evocative
music is played with beauty and sensitivity by Stokowski and the
Another beautiful extended excerpt from Wagner's Ring des Nibelungen
from this concert was the finale of Die Götterdämmerung. This
includes some of the most dramatic music of the Ring. It
depicts the funeral and the funeral pyre of Siegfried, where Brünnhilde
sings of her love for Siegfried. She then rides her steed Grane
onto the funeral pyre. The Rhine overflows,
Hagen attempts to seize the ring, but the Rhine maidens regain it.
In the distance, the sky is filled with fire, and Valhalla is revealed
consumed in flames. Valhalla then collapses with Wotan and the
gods seated within. Brünnhilde, through her love for Siegfried
has cleansed the world of its corruption. Underlining this
transformation, the key of the final music changes from E flat to D flat,
concluding Wagner's four operas telling the story of the Ring.
Incidentally, in this excerpt, there is a very faint audio image of
what seems to be an soprano operatic voice singing faintly in
the background at about 6 minutes into these excerpts. This
is present on every pressing of the Bell Laboratories 33 RPM Long
Playing disk I have heard, so I conclude it intruded in some way into
the master tape of this excellent transcription of the original
78 RPM master disks. It is noticeable only at elevated
volumes, however, and should not detract from the enjoyment
these performances provide, more than 75 years after the
original live concerts.
April 29, 30, 1932: Die Walküre Ride of the Valkyries
Also from this concert is the famous Ride of the Valkyries from
Die Walküre. This excerpt is partially in stereo.
This has been restored from the Bell Laboratories LP recording
by the mastering and restoration engineer
, in an excellent and subtle restoration. (You can contact him at
Marcos Abreu - Audio mastering and restoration services, email address:
Keller and Bell Laboratories 45° Stereophonic Grooves
Arthur Keller later had the inspiration of a technique to record
two channels of stereophonic signal in one record groove.
His idea was to record each channels at 45 degrees from vertical
and 90 degrees from each other. Keller was awarded US patent
2,114,471 for this method. As described below, Alan Blumlein
working for EMI in Britain also developed this idea, but from the
information I have seen, it would seem that Arthur Keller and Bell
Labs probably were the first. This seems yet another example
of the many in science and technology of two independent minds
reaching the same idea or discovery at about the same time.
The 45 degree stereophonic recording
of two channels within one record groove was not exploited commercially
in the 1930s or 1940s, and Arthur Keller's patent eventually lapsed,
and seemed to have been forgotten. This solution to stereophonic
reproduction seems to have been re-invented in the 1950s by Westrex
of Hollywood, California. This Westrex was a later spin-off of
Bell Labs technology. Westrex of Hollywood, California used the
the 45 degree stereophonic recording system for their Westrex stereo
LP long-playing stereo disks.
Alan Blumlein and EMI development of Electrical and
Another early pioneer of stereophonic recording was done at
EMI in Hayes, Middlesex, UK by the brilliant young scientist
Alan Blumlein in the 1930s
Blumlein had joined the Columbia Graphophone 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
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 technology and patents. 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 early 1925,
somewhat before the Victor Talking Machine Company. (Read
about this on the page
Licensing the Westrex Electrical System
This Columbia license may have influenced Victor also to license the
Western Electric 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 Western Electric process. Blumlein also
developed a moving coil microphone at about this time.
Interestingly Edward Christopher 'E.C.' Wente of Bell Laboratories had developed a moving coil
microphone in 1928, which received US patent 1,766,473 in 19319.
Wente's Western Electric Model 618A of 1931 was nearly flat in
response from 30 to 15,000 Hertz, and its low impedance (30 Ohm)
allowed long cables without significant signal loss10.
The 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 studio 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, 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. This was similar
to combining the old 'hill and dale' cutting method of companies such as
Pathé with the horizontal cutting of companies such as Victor and Columbia.
Additionally, Blumlein did later work on 45 degree oriented
groves, which have the advantage of avoiding channel differences
arising from factors such as rumble and vibration.
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 reinvented the technique.
Westrex, a spin-off of Western Electric was sold to Litton Industries.
It prospered for a time in both stereo recording and Hollywood sound
systems. Westrex developed the stereo Westrex groove design,
reinventing the 45 degree orientation 14.
1933 Long Distance Concert - Philadelphia to Washington
On April 27, 1933, Bell Labs, Harvey Fletcher and Arthur 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
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.
Stokowski at the controls in the 1933 Washington DC stereo broadcast
with 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.
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.
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
14 pages 1686-1693. Davis, C.C. and Frayne, J.G.
The Westrex Stereo Disk System. Westrex Corporation,
Hollywood, CA Proceedings of the IRE October, 1958 Volume: 46, Issue: 10.
If you have any comments or questions about this Leopold Stokowski site, please
e-mail me (Larry Huffman) at e-mail address:
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