[Dixielandjazz] Correct Record Speed

[Stephen G Barbone]

Here is Part 3 of correct speed from Neville Dickey



Analysis is made more difficult by the fact that the speed sometimes  
varied during the cutting of a track due to more power being needed on  
the outside grooves, or during loud passages. Also, there was  
absolutely nothing standard about this; the speeds seem to vary from  
56.6 to 60.2 RPM for no very good reason. It seems that all records  
were made in easy keys, and very slow, allowing musicians time to  
improvise. Jazz playing is not rehearsed note for note, nor written  
down, even though most have head arrangements and some, for example  
the later Beiderbeckes, had written backing for spontaneous jazz  
improvisations.

During the Armstrong Hot 5 and 7 recordings they played in a  
deliberatly relaxed style which sounds fine at 78 RPM; but at 58 RPM  
Armstrong's vocals appear to be somewhat ponderous, and sung at the  
lower end of his range, which I believe was all quite deliberate. On  
the other hand, Lil Hardin's vocals seem fine at 58, but sound mouse- 
like at 78 RPM. Interestingly, a large cymbal was used for these  
recordings which achieved a wonderful but false sound at 78 RPM.

The speed of a batch of Armstrong Hot 5 recordings, made by Okeh in  
early 1926, has been investigated by Norman Field who concluded that  
all these records were recorded at 82.17 RPM so should be replayed  
even faster than 78 RPM. In my opinion this particular set of  
recordings was made at 60.2 RPM. Clearly Norman and I have not been  
able to agree on this point, but we do agree that 'there was something  
curious going on' and that 78 RPM was not the recording speed.

Although my wind-up gramophone has long since gone, I listen to jazz  
on CDs, but it is easy to check the recording speed. This can be done  
by noting the key at 78 RPM, by playing my cornet with the record,  
then varying the speed to find the key that sounds plausible, noting  
the key in order to find the pitch difference in semitones at the two  
speeds. A quick calculation using the ratio of frequencies of musical  
notes, from an acoustic table, gives me the speed at which the disc  
was cut. For example,Dippermouth Blues by King Oliver in 1923, is in C  
at 78 RPM, but appears to be correct in the key of G. C is 523.25  
cycles/sec, and G is 392 cycles/sec, so the original cutting speed is  
78 x 392, divided by 523.25; that is 58.4 RPM. The question then  
arises: Why were all the records cut at about 58 RPM? The answer is  
that any intermediate speed would result in some very unlikely keys at  
78; whereas at 58 to 75 equates to all keys being reduced by one flat,  
for example G to C.

Many musicains and jazz enthusiasts to whom I have spoken have mixed  
feelings about the theory that all recordings were made at such a slow  
speed. My analysis of possible keys indicates that all the records  
were made at approximately 58 RPM, at which speed they sound relaxed  
and carefully improvised. Where there is no proof or written evidence,  
it is only the recordings themselves that can tell the true story.  
First, listen to a track at 58 RPM, which sounds perfectly plausible;  
then follow it by the last few bars again, but at 78 RPM, and you will  
probably be quite convinced.