Many trained musicians are unaware of their sensitivity to tone at the vibration level until they experience something wrong. Yesterday a fine pianist expressed her dismay that the horn entrances in Brahms symphonies sound of tune. I should mention that this pianist is also an experienced a capella singer with an excellent sense of centering vocal pitch.

Every combination of unlike sounds involves some compromise of temperament: a vibration here or there makes a huge difference in orchestral music, as it should also in chamber music. Why aren't we more aware of this source of magic and potential trouble?

I believe that the image of discrete pitch embodied in the piano keyboard has locked us into an expectation belied by experience, leaving us mightily confused rather than intrigued. The horns are not out of tune: the temperament of horn intervals is not the same as that of strings. It's the same dilemma as in the Mozart piano concerto in which the piano sounded out of tune (a post in July, 2009 describes that event).

The happiest listener is one who not only tolerates the differences but relishes the tension between them.