One of the most important decades in tango music was from the time from the invention of the electric microphone 1926 until around 1940 when the standard of 78rpm was finally established. It was also then when the modern chamber key of a'=440hz was widely accepted.
Osvaldo Fresedo was the first "modernizer" of tango as he was turning to the new modern chamber key as early as 1931. Let's look at Fresedos recordings and how he was dealing with this key shift in order to understand how complex and important this topic for tango recordings is.
Without any doubt the famous "Sexteto Fresedo" of the years of 1925-1928 was recording entirely on the old chamber key that was mostly defined by the in built tuning of the bandoneon of a'=435hz. When Fresedo finally arrived in New York 1929 he most likely found a musical society which appeared to be very modern as the "new" chamber key of a'=440hz was just about to be established. But Fresedo, of course must have been carrying his old 435hz bandoneon and therefor all recordings he made in New York in 1929 and 1930 are referring to this old chamber key. Coming back to Buenos Aires in 1930 he was obviously eager to get modern american influences into his music. He restarted recording in 1931 with swing and foxes tracks and all these recordings 1931 and 1932 for Brunswick Argentina are recorded in the modern chamber key of A'=440hz. Though one exception was the recording of "Tango mío" with Agustín Magaldi. Why they decided to record this track with the old chamber key we do not know - maybe Magaldi insisted in that!?
Later in 1933 Fresedo switched the record company and for Victor he started recording again in the old chamber key. of a'=435hz. Maybe someone in the Victor recording company insisted to stay in the old key until finally in 1934 Fresedo recorded for the first time with a brand new instrument, the Vibraphone. Although this instrument was invented some years earlier, it became fashionable in US american Jazz music after Luis Armstrong's hit "Memories of you" of 1930. The Vibraphone was built in a fixed tuning A'=440hz. No tuning possible. Obviously together with the informations of international classical music stars which were touring Argentina regulary at that time, Fresedo could finally convince his record company to switch to the modern chamber key. On the 27th April 1934 he recorded the tango "En la huella del dolor" in the modern tuning and from this day on all his recordings are referring to this key.
- The tuning of
the instruments did change. Since during the 19th century international
exchange of music got more and more important, classical musicians and
ambitioned societies tried to establish a regular standard. Still until around 1940 the new tuning standard of A'=440hz was not everywhere and for all
instruments established - but some regions, manufactors, musical
societies and of course some musicians did tune up to this new A'=440hz
earlier. The difference between 435hz and 440hz is quite good audible
and is nearly the half of a semitone step. As for the bandoneon we
can be shure that all instruments manufactured in Germany before
worldwar II were built with an A'=435hz. Unlike string instruments, a
bandoneon once built cannot easily be retuned differently and obviously
these German built bandoneons played together for two decades with the
other instruments in Argentina.
78 rounds per minute standard cannot be regarded in general as valid as
the later standards of 33rpm or 45rpm for vinyl discs that we know. How
different companies in the world established the 78rpm as a standard,
has to be seen as a shifting developement due to technical increases
that took place slowly w h i l e these companies were already about to
sell products. When it did start that the idea "selling records for an
intended playback of 78rpm" was handed out to the costumers of record
and record-players buying, neither all the recording machines, nor all
the record players used were precisely set to 78rpm. We have to deal
with the fact that until the 1940s we shurely find many recordings that
will not run correct in speed when played at 78rpm. To confuse us,
you also will find some they do, as obviously under circumstances some
shellacs were manufacured with more precision than others. We can easily
assume that this was a question of money.
|Victor factory 1920|