There are several cues I can use each of which involves a different and tricky set of computations.

One is to build a set of vocal formant spectral envelopes and match the shapes across the songs. This would get the relative speeds calibrated.What's tricky about this is finding places where he sings the same vowel in each song. Fornuately there is a lot of redundancy between blues lyrics;man, she, lordy, lord, blues, raining/morning etc etc.
Another ones is to estimate the reverb time of the recording room(s) and correlete those. This is particurlarly tricky because there are few impulsive sounds to do this with and not much room ambiance is recorded anyway.

Then we can look at guitar transients. Transients (from plucks, for example) have the same structure whatever pitch you pluck and become very unnatural sounding if they are stretched.

There are probably some places where he knocks the guitar with the slide or places we can recover the top-plate resonance frequency. These can all be correlated assuming he played the same guitar throughout.

The real trick would be to find an absolute pitch reference in the recording. The only one of those I can think of is 60Hz or some harmonic of it from power lines. This would be the best way but in those days elecricity and electrical devices were not as commonplace as they are now. Also we have to contend with such contamination that might have arrived in the transfer from 78 to CD.

My response on hearing the slowed version:

Sounds like the original recordings slowed down.

[This message has been edited by waxwing (edited January 29, 2004).]

I do know for a fact that some of Bling Boy Fullers recordings were speeded up. Try playing with BBF. A song could typicaly start in E. That's using C first position shapes with a capo on the fourth fret. By the end of the song, it's gone up to F. That's manipulation !

I don't really know what to believe!
I think there are so many places for errors to occur:

Pitch at which the guitar is tuned (no guitar tuners then)
What Key tuned to
Use of capo or not, and which fret
Speed/tempo played during recording (while nervous etc) compared to gig (faster OR slower BUT more relaxed ?)
Speed of recording equipment
Speed of playback on to mastering discs (and speed of those)(etc etc)
Speed of playback while recording onto 78's
Speed of 78 record(s) on recording machine/device
Speed of playback on 78 record players (likely to vary ?)

Speed of 78 when played for transfer onto Digital Recording Medium for manufacture of CD's
Playback speed on CD's (unlikely to waver about ?)

Personally, apart from the difficulties of playing the "12 fret" bits on a 12 fret neck guitar when capoed, I actually find it easier to play his tunes capoed up a few frets - on the guitar AND for singing in a higher key.

Also, I don't buy the idea that the old Delta blues guys tuned their guitars as high as they could go without breaking strings, for extra volume. I would have thought that in those days (Depression etc etc) the lack of cash and availabilty of guitar strings (?) would mean that the last thing a guitarist would want is to risk breaking strings left, right and centre !! Not think ?

What are the implications of this, if it's true, for what the "correct" sound would be for Blind Lemon Jefferson, Charley Patton, and all the other people of that time? If this was done for RJ's recordings, then it might have been common practice, and all our impressions of prewar blues players might be altered a little bit.

Why haven't we heard any comments on this subject from Robert's contemporaries? After listening to the samples, if there really was THAT much difference between his recorded voice and his actual voice, wouldn't SOMEBODY who knew him have made mention of this at some point?

I watched "The Search For Robert Johnson" not too long ago. If anyone hasn't seen it, there's a scene wherein John Hammond plays Robert's recording of "Love In Vain" for Willie Mae Powell. (It was supposedly written for her) She didn't bat an eye. She didn't say "Gee, his voice wasn't that high!" Wouldn't you think someone as intimate with the man as she was, and probably saw him perform as much as anyone, would have made that observation?

I've listened to the clips, and I'm not buying the theory at this point.

Stuff that happened a long time ago happened that way cause it was a long time ago. Woulda been cool to have been there and seen it/heard it all happening in real time... but those artifacts is what wees got.

Could you remember whether someone played a song in A or F# 65 years ago? And although the slowed vocals do some a bit different, they are not earthshaking dissimilar.

After years of hearing them one way, the tunes do sound a bit wrong at the lower speeds. Johnson sounds a bit more like a mortal, and his guitar work a touch more pedestrian. But even today, speeding or slowing recordings is done quite often. I’ve done it a few times to slow down an adrenalin laced tempo, or to get a backing track closer to the singer’s range.

This is an interesting topic, and well suited to most of our specific tastes here on the forum. I would love Adrian to come up with a understandable layman’s method of comparing the recordings.

In the meantime I will return to my scrutiny of the photo of Charlie Patton, which I now find to be completely legitimate.

Also, My Black Mama sounds so much like Son House's phrase form Deathletter blues that you can't help but know that's Son's influence shining through. At full spead I never heard that influence except in the words themselves. Now I hear it musically too.

It may be that recordings were sometimes sped up on purpose in order to get more music on them, but I wonder also if the recording speeds had not yet been standardized and we're hearing artifacts of the technology. Recording technology was still pretty young, even in the 30's.

Also in your book you provide an interesting note about pitch changing due to re-tuning during the recording of two sequences of songs: on page 96 in your comments on Last Fair Deal Gone Down and page 170 in your comments on Traveling Riverside Blues. I just hadn't paid much attention to it before!

So many interesting twists to this story!