Resending, with apology if this was sent previously:

From: Doug Pomeroy <[log in to unmask]>
Date: May 26, 2009 6:45:21 AM EDT
To: [log in to unmask]
Subject: Re: [ARSCLIST] Robert Johnson RPM debate
Reply-To: Association for Recorded Sound Discussion List  
<[log in to unmask]>

Vocalion probably used a spring driven cutter, and they were
less reliable than the weight driven ones (according to Ralph
Peer).  If we knew Johnson tuned his guitar perfectly (re:
'A' 440), it would be a piece of cake.  He probably didn't,
but still it was probably not too far off, especially if he
played with other musicians (e.g., harmonicas).

Doug

>
>
>> Date:    Mon, 25 May 2009 11:18:13 -1000
>> From:    Malcolm Rockwell <[log in to unmask]>
>> Subject: Re: Robert Johnson RPM debate
>>
>> James -
>> I've read the arguments and heard the pitch shifted samples and  
>> say it's
>> possible the recordings are pitched high. This would mean one of  
>> three
>> things: 1) Robert really sang that way; 2) the material was  
>> recorded too
>> slow; and/or 3) the final pitch was modified by dubbing prior to
>> manufacture.
>>
>> I tend to go with #1, mostly because I've always heard him the way he
>> has been presented on LPs and CDs and my ear is used to that. The
>> samples are interesting food for thought, though!
>>
>> #2 is possible mostly because machines do run slow (there's very  
>> little
>> homogenity of 78rpm recording speeds company to company, and  
>> session to
>> session within the same company. Add that to playback speed  
>> variations
>> and, well...). What was the power source in Dallas? 110 VAC? 120  
>> VAC? Or
>> was it DC voltage? If AC, was the frequency (usually 60 Hz) solid, or
>> did it wander? What kind of motor did the portable recording lathe
>> use... AC, DC or counter-weighted (mechanical)? There are just too  
>> many
>> variables here.
>>
>> #3 requires forethought and since there was seemingly so little of  
>> it in
>> #2, I doubt this scenario. Producers are not going to agonize  
>> about this
>> kind of thing; to them Robert was just another blues picker. But who
>> knew what he'd become 60 years later or that any of this would  
>> matter?
>>
>> Good luck with your research!
>> Mal Rockwell
>>
>> *******
>>
>> james mendenhall wrote:
>>
>>
>>> Hi, Arsclist
>>> I am doing research about the rpm debate of the Robert Johnson
>>> recordings.
>>> Does anyone have any information for me?
>>> And, is this all speculation or has there been proof found that they
>>> are indeed too fast?
>>>
>>> thanks
>>>
>>> james