[78-L] Concert pitch (was: no subject)

[Chris Zwarg]

At 17:13 16.10.2008, you wrote:

>From: Michael Shoshani <mshoshani at sbcglobal.net>
>
>>This provides a pitfall for radio collectors who attempt to adjust the
>playback speed of transcriptions of this era by pitching them at A=440.
>The only corrrect way of adjusting the speed is to pitch the record so
>that the notes (usually C-A-F on the Deagan 20 or G-E-C on the Deagan
>200) are at A=435. 
>
>> NBC went to electrically-operated chimes after the hand-struck chimes
>were phased out; I don't know whether these are A=435 or A=440, because
>I have yet to hear a recording of these chimes that I can know with
>absolute certainty are played back at the same speed at which they were
>recorded.
>
>MS  >
>
>
>Ah Ha!  This might be where the videotape I have of the Rangertone
>chimes comes in.  The assumption would be that this has to be at the
>correct playback speed to maintain sync.  But I still haven't gotten
>around to dubbing it to disc for you yet.  

24 fps cinema film would sound VERY slightly flat on a NTSC videotape (23.95 fps, changed to 29.97 fps NTSC-TV standard by doubling every fourth frame), but 4% sharp on a PAL video at 25 fps without any frame-doubling. That does of course not preclude heavy momentary pitch changes ("wow") as neither film projectors nor video recorders are very good at avoiding speed fluctuations - in fact, if the tape has become slightly stretched with frequent use, video playback will vary the speed in attempting to keep a steady flow of 25 resp. 29.97 frames per second at the output, preferring picture sync over audio quality.

Chris Zwarg