Hi Steve,
Years ago I started checking the pitch of every single recording which came my way.The tape recorders without servo circuitry, like the Ampex 350 and most non-pro decks are especially difficult to fix. There is some software available for making gradual 
corrections over time, but these programs are not a panacea.
I would add that a range of 15 to 20 cents is close the the limit of human hearing acuity, 
at least for those of us without perfect pitch. But I totally agree we should correct alldetectable errors.
Doug PomeroyAudio Restoration and Mastering Services
193 Baltic St  Brooklyn, NY  11201-6173
718 855-2650
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    On Wednesday, April 10, 2019, 10:11:33 AM CDT, Steven Smolian <[log in to unmask]> wrote:  
 I've found about 50% of the mono LPs I've been dubbing are off-pitch, mostly
sharp, or so my Korg tuner informs me.  Both the Menotti Sebastian with
Stokowski and his Violin Concerto with Spivakovsky and Munch are sharp maybe
15-20 cents.  I tune to fixed pitch instruments so I bypass vocalists and
string players whenever possible- in the regard, at least.  Some other RCA
LPs are accurate and match what the strobe on the TT tells me, so it's not
the playback that is at fault.  


This is not tape drift- a problem encountered on old tape masters- the Ampex
350 was prone to this problem- when splicing together the end  of one eel
with a segment from the beginning of another or if done on two recorders
should they have been running at slightly different speeds..  


This seems an unreported problem except for my previous post on this issue.
If the users of older recordings are to draw performance and scholarly
information from "how it was done," then straight, unchecked for this issue
33.33 dubbings are perpetuating misinformation.


Steven Smolian