Turntable speed accuracy

How can correct turntable speed as well as excellent speed stability possibly NOT matter and be of the utmost importance? Rhythm and time is where the heart and soul of music lies. Any technical considerations that may have an effect on these are of the utmost importance. I am constantly perplexed by how often audiophiles agonize about minute changes in areas that affect the tonal/timbral characteristics of their audio systems, but are willing to forgive much larger deviations from truth in the area of time and rhythm. 

I hope we can agree that our audio systems exist to be at the service of the music. Musicians, not audio systems, make music; and musicians  give a great  deal of importance to performance considerations that relate to the perceived effects of correct playback speed and speed stability. The changes in pitch as they relate to performance standards are more subtle than what is generally discussed in relation to technical accuracy in turntable systems. These considerations are not arbitrary, but relate to the emotional impact that tuning has on the music. This is not only the players' consideration, but sometimes also the composer's intent. It is well 
documented that many composers chose to compose in a particular key because of the emotional effect of one key versus another. Likewise, orchestras or individual players will often tune their instruments to achieve a particular sound and it's resulting emotional effect. If we are going to worry about the effects things like slightly raising or lowering VTA, why dismiss the effect of these other considerations when these relate much more to the core of the music? 

Speed stability is even more important as it relates to these considerations. Excellent comments have been made above about the importance of these. There is no question that extremely subtle deviations from absolute pitch stability are quite audible. As has been pointed out, even the very best belt drive tables suffer from these distortions. What is really insidious is the effect that these distortions have on the emotional impact of the music, and the ability of the music to engage the listener. As this relates to musicians' performance standards, I would like to point out that the effects from the absence of absolutely stable playback speed on the music is not nearly as subtle as the considerations that musicians give to absolutely stable and accurate time and rhythm during a performance; these can be the effect of anything from simply the mediocre sense of rhythm on the part of a particular musician, to wether a musician had too much coffee that morning (I kid not). If we can agree that these things matter during a performance, how can similar effects not matter a great deal during playback?

" Musicians play things in certain keys and tempos for a reason" - Atmasphere

That's exactly right, and the point of my earlier comment. Deviation from the musicians' intent has a significant impact on the music. That's not to say that the music can't be enjoyed if there are small deviations, but there is no question that it's full impact can't be realized.

Atmasphere, I agree that speed stability affects sound staging. I also believe it affects perceived detail retrieval, and timbre. I use a straight
tracking arm (ET2), and I still hear improvements in staging when speed stability is good. When it is not, staging is not as defined and is slightly confused.

I think that in our attempt to arrive at a scientific explanation for all the perceived aspects of music playback, we overlook the very real possibility that there are many things that we don't yet fully understand; probably never will. As I said in an earlier post, time and rhythm are where the heart and soul of music lie. The subtleties of rhythm are extremely fine
and can be very elusive for the record/playback process. The relationship
between rhythm and timbre is likewise very important and difficult to understand. For example: experiments have been performed that show that the characteristic (individualistic) recorded tones produced by players on any given instrument are very difficult to tell apart if one removes the initial attack of a note, and listens only to the sound that happens after the attack. Speed instability alters the sound of the initial attack since the initial attack is connected to a point in time. With this in mind, it is not difficult to understand why speed instability can affect just about every aspect of sound.

Jtimothya, I don't think you are serious (correct me if I'm wrong), but to elaborate on my point: a great drummer playing alone can get the juices flowing with a great groove. Now, imagine a (potentially) great melody played or sung with bad rhythm. The end result can be painful.

I give up.

Very well put, Learsfool. The importance of coherent rhythm can't be stressed enough. On a related note (and the subject of another thread), it is ironic that in spite of it's technically "superior" speed stability, digital recording technology can suffer from rhythmic blandness. It is not only rhythmic accuracy from one point in time to another that matters, but what happens in between; the motion moving away from one point in time and leading up to another. That is what gives music it's thrust and swagger.

While there is tremendous value in technical explanations for some of the perceived problems with vinyl playback, I think it is important to remember that those possible explanations are incomplete, and don't fully address the fact that what we are ultimately concerning ourselves with is an impossibly complex and fragile thing: the FEELING in music. Small speed stability problems that affect the perceived feeling of the music, wether caused by run-out errors or rotational speed error, are probably beyond the capability of any known measuring system.

I have (like all of us posting on this thread) struggled to make my
expensive belt-drive turntable as speed-stable as possible. Thread drive and a motor controller have improved the situation to a barely acceptable point. I say barely acceptable because I can still hear problems compared to the rock solid stability, and fabulous swagger that live music can have. In addition, the very same LP that has no perceived run-out issues when I use thread drive, will sound speed unstable when played using the rubber belt. This, in spite of my strobe showing that the speed should be rock solid. NOT!

Thuchan, I reluctantly admit to being a "neutrality apostle". But I am reluctant only because, IMO, the term neutrality is usually misunderstood. In your comment you pair the term neutrality with sonic-footprint. From my vantage point, sonic footprint is, by definition, usually the result of distortions. Neutrality (or however close a component gets to it) is a measure of musicality. In other words, a component that is truly musical IS closer to neutral. "Precision control" allows musicality.

Regards.