Intonation
Cleanness of pitch; also the opening of the chant delivery.
What it means
Intonation designates the accuracy of pitch in singing and playing. Alongside this the word carries a second, older meaning: in liturgical chant, the opening formula with which a cantor intones a chant before the choir enters. A third use is known in instrument making, where voicing (intonieren) means the tonal fine-tuning of an instrument — with the organ the adjustment of the pipes, with the piano the working of the hammers.
Musical use
For practice it is decisive that clean intonation does not mean hitting every note on a fixed value. On instruments with flexible pitch — strings, winds, singing voices — the height of a note follows its harmonic context. The leading tone is taken close to its goal, the third of a major chord somewhat lower than on the piano, so that the sonority becomes calm. A G♯ as a leading tone and an A♭ as a lowered degree are therefore not the same note, although they coincide on tempered instruments.
The reason lies in acoustics: pure intervals rest on simple numerical ratios that do not fit together without contradiction into a closed system — the difference is called the comma. Equal temperament distributes it evenly; whoever can intonate freely decides, by contrast, anew in every sonority.
To this come external influences: temperature and humidity noticeably change the tuning of wind and string instruments.
In Gregorian chant, intonation designates the beginning of a chant that a cantor delivers alone before the choir enters. In organ music an intonation is a short prelude that gives the pitch. In organ and instrument building the term means the tonal adjustment of the individual pipes.
Performance practice
Tune by the sound, not by the display: when a sonority is pure, the beats stop, and this becoming calm is the most reliable criterion. Practise with a drone or a held fifth instead of with a tuner. Always check your intonation against a lower reference note, not in isolation. And, in the ensemble, check first the fifths and octaves, then the thirds — they are the most sensitive.