Even a 1% static error alters the essential character of the music only very slightly, and even then usually only in direct comparison with the correct speed.Alex,
That's the first statement you've made that I'll specifically disagree with. Given sufficiently transparent yet harmonically complex music, a 1% static speed deviation is quite audible. The music's harmonic structure will be damaged.
I'm not referring to anything esoteric. Mozart's orchestral scores are a good test. Nothing seems simpler, but his harmonic relationships are far more tightly inter-related that is usually appreciated. Change playback speed by 1% and they fall to pieces.
To be fair, this does require a very transparent sytem to be audible. Bloat or overhang from any component will readily mask the harmonic damage from a 1% static speed error. My old c-j and Bent components did. So do Aesthetix and Supratek, for that matter. Dan_Ed, Jyprez and Swampwalker could attest that our Nick Doshi stuff has the requisite transparency. When they visited recently I didn't specifically demonstrate the audibility of a 1% TT speed error. But I could have.