Jerry asked why anybody should know better than Stockhausen about the necessary tempi for his works. I do not think that Stockhausen would have approved that a performer would express his "freedom" of interpretation by changing tempi. Quite the contrary, I am sure that he was convinced that "Werktreue" is crucial for the performance of his work, and he saw himself as a composer who added much to the evolution of compositional technique especially by the refinement of tempo. Therefore, it is not the question whether one is able to discriminate metronome .5 differences but to stick as much as possible to the goal of becoming able to do this. (I just want to add that Stockhausen claimed to be able to discriminate 1 dB differences in the studio which seemed to be impossible for his sound engineers. So that is a goal, too.)

Let's not forget that he also claimed to have not only perfect pitch, but perfect frequency.

Hm.

Joe, while I understand the difference, I cannot recall Stockhausen saying he could unfailingly identify frequency as distinct from pitch. Where did you find that, or was it something he said in your presence?

At the first Sound Projection class in 2008, Kathinka and Brian handed out a frequency chart as they explained that Stockhausen had perfect frequency.

Hi Joe,

Did they explain how Stockhausen discriminated between frequency and pitch? What I mean is, how would he describe the difference, since pitch is the subjective response produced by frequency, influenced by other factors such as intensity?

I'd like to see the frequency chart if you could post a scan...unless it's just basic info like A=440, etc...

The chart is a fairly unremarkable list of frequencies and their pitch correlation. There was not much discussion of Stockhausen's ability to discern the differences in hertz levels, just a statement that he was able to.