I suppose anyone who plays or sings with other poeple recognises the situation where people have very differing ideas about what is 'in tune', and what isn't. The whole thing can easily degenerate into an acrimonious argument, settled by the force of personality of the dominant person in the group, producing a situation when there are some doubtful winners and some clear loosers.

A brilliant personal technique is so much in focus these days that there is perhaps less awareness of how differently people behave when they do things with others - the dynamic of the musical group, we could call it 'muscial group dynamics': shaky, incomplete understanding of the factors involved can easily produce a basic insecurity; tentative doubts may lead to subjective opinions, even irrational ones; these opinions may be experienced by others as criticisms, even as accusations; and these can easily lead to anxiety and defensive behaviour, perhaps even to half-formed, inexpressable feelings of guilt.

None of this can be said to be conducive to that inner harmony within a musician's body, and that concord between musicians, which are prerequisites for a sympathetic concentus, a sharing of feelings with one another and with those who may listen - musica humana. Of course it is true that since the advent of the 'genius cult', of atonal music, of modern jazz, of punk-rock, there have been many forms of music-making whose prime goal has not been to evoke a feeling of well-being and harmony in the listener - some people make music to compel others to admire them, some to excite others to revolution, others simply need to give vent to their own frustrations and dissatisfactions, and have no special concern for the emotional state of any listeners there may be. But up to the time when the Romantic movement started turning the old order upside down, musicians traditionally considered their aim as being to induce harmonic concord in the body, and in the soul, of the listener: not in an airy-fairy abstract way, but concretely and objectively, by using well-proven poetical and rhetorical ideas, and, as a prerequisite, using combinations of notes which are in tune and which produce well-sounding (consonant) harmony.

It is still possible to produce this effect nowadays, and one may assert that the experience is rewarding for all concerned to a degree quite out of the ordinary.

The first step must be to reach a shared understanding of what is, and what is not, in tune: of what can be, and what cannot be, in tune: and of what objective standard of measurement can be used. These notes were written to help reach such an understanding.