The decade of changing chamber key

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.

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Further explainations:

In the past two conditions had superior influence on the recorded music.

1.  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. 
   
2. The 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.  
   

Being digitalized today many recordings of the past are copied several times due to technical progress. If not transfered as a new from an old shellac disc being found somewhere, we mostly have transfers from vinyl LPs. For the production of an Lp usually the old shellac discs were recorded on tape and from that tape the Lp matrix was printed. Sometimes sound technicians tried to somehow fix the sound while transfering to tape and sometimes corrected the speed, sometimes corrected frequencies, sometimes added reverb. Even many "original" Lp's are lost and there are reprinted copies around, where companies copied old Lps to tape in order to reprint a new one. While working this new copies sometime technicians again did their best to raise the result a bit. When Lps or even original Shellacs today are digitalized, again technicians try to do their best to make a nice result and work on pitch and sound as they can. Of course the conditions of the used vinyl or shellac discs got a huge effect on the result - as the capability of the technician does. 

As many record collectors and technicians are no musicians, we often find either ignorance towards the question of chamber key used while recording, or misunderstandings about this important condition.

Also the myth of a valid 78rpm standard leads to errors.

Turning to an existing old recording we have to find out the chamber key that the musicians used while recording and this is a major question for every recording of the decade of 1929-1939. As a matter of fact before 1929 we can surely indicate all recordings in Argentina to A'=435hz. All recordings after 1939 will have a VERY good chance to refer to A'=440hz - only if we come across recordings, where someone who might have insisted to continue playing his old 435hz bandoneon, we'll get into trouble and we have to keep an ear on that!

The recordings of the decade of changing chamber key A'=435hz to A'=440 (1929-1939) leaves us very doubtful with each recording as no one has ever precisely documented this major change. 

 

To solve this problem one needs to find the key of the recorded tune which can be done easily by looking up the sheets - if available and only if they didn't alter the sheets to make the tune more comfortable for a singer while recording or later for the public to play. And that did actually happen around 5-10% of the time. 

Of course all that is even more difficult when sheets are not available. Then we can only list the two or three possible keys for each piece of music which does make any sense at all. There will always be a limit to the range of speed - up or down - before the recordings get rediculous by ear. The decision of which key indicates the correct speed and therefor correct pitch of the recording, must be drawn due to music theory where melodies are layed on an existing key and cannot be composed on other key. Sometimes it can be a help to know the voice of the singer. For example a fan of Gardel's music will have a good chance to indicate the correct pitch, once the choise of results is limited anyway to two or three.

Each doubtful recording has to be corrected in pitch to the key of the tune TWICE. One referring to A'=435hz and another to A'=440hz. In a timeline of about 20 recordings under same conditions (same artists, same year, same record company) a trained ear can find out if this period was either recorded under A'=435hz or A'=440hz ...and therefor we find the correct pitch.

Victor factory 1920