Whole-tone step
A step of two semitones.
What it means
The whole-tone step is the movement by two semitones, that is, by a major second. It is the larger of the two steps from which the diatonic scale is built, and the more frequent in it: five whole-tone steps and two semitone steps yield the octave.
In the notation
It is written as a step to a neighbouring degree — from a line into the neighbouring space or the other way round. Whether this step is a whole tone or a semitone is not directly revealed by the notation: it depends on which natural notes are involved and which accidentals apply. Between E and F as well as between B and C there lies by nature a semitone, between all the other neighbouring natural notes a whole tone.
Musical use
The distribution of whole-tone and semitone steps is what shapes a scale. In major they follow the order whole–whole–half–whole–whole–whole–half; if one shifts the starting point, the church modes arise from this, whose character results solely from the changed position of the semitones. The whole-tone scale consists exclusively of whole-tone steps and therefore has no centre — no note is singled out from the others, and precisely this makes up its floating sound.
Melodically the whole-tone step acts more neutral than the semitone: it carries no compelling direction in itself, whereas the semitone pulls. That is why Mixolydian music, whose seventh degree lies a whole tone below the root, sounds more open and less goal-directed than major.
In the diatonic scale, five of seven steps are whole-tone steps. The relation of whole tones and semitones determines which mode is present. In just tuning one distinguishes the major whole tone with the ratio 9:8 from the minor whole tone with 10:9.
Performance practice
When practising scales, take deliberate care to notice where the semitones lie — they determine the character, the whole tones are the rest. In intonation the following holds: whole-tone steps are taken rather wide, semitones with leading-tone character close. And sing an unfamiliar scale before you play it; the position of the semitones imprints itself faster by hearing than by calculating.