In the heptatonic (Greek "seven-tone") scales within an octave are formed as scales from eight tones, of which only seven are counted as genuinely different due to the same tone quality of the first and last tone. All diatonic scales used in Western tonal music, such as the major and minor scales, are heptatonic. Other heptatonic scales, which are often not diatonic, can be found primarily in non-European musical traditions.
There are several methods of constructing a heptatonic scale
In the derivation outlined below, interval designations such as fifths or octaves are initially to be understood in terms of the absolutely audible proportions that correspond to physical frequency ratios , e.g. B. 3: 2 or 2: 1. In the traditional European heptatonic systems thus constructed obtain tone levels and the proportion to the tone corresponding to the interval Latin name; z. B. the proportion between the fundamental tone and the fifth tone always has the auditory impression of a fifth. Depending on the type of construction ( mood ) this is exactly right, e.g. B. with a perfect fifth (3: 2), or only approximately .:
- A possibility that has already been tried and tested in antiquity results from the octave-shifted sorting of seven fifths , with the tone d as the middle of the root tones being the starting point:
f - c - g - d - a - e - h → d - e ^ f - g - a - h ^ c (- d)
The resulting series of tones consists of whole tones with the proportion 8: 9 and semitones (indicated by “^”) with the proportion 243: 256; she is therefore in a Pythagorean mood .
- A system in pure tuning is created by the consonance principle: By harmoniously dividing the octave into fifths and fourths , the fifths into major and minor thirds, and finally into whole tones and semitones, a scale is obtained that corresponds to the overtones of the natural tone series .
- The equal temperament tuning assuming a can diatonic scale by selecting from the chromatic form tone sequence.
- Another possibility is the formation of tetrachords . These four-tone scale sections have two fixed frame tones that form a fourth, and two fill tones that can be moved depending on the tone gender . In the Greek tone system the two tetrachords are separated by a whole tone or connected by a common tone.
Almost all seven-note scales (major, minor, church keys , Hungarian scales, blues scale ) are made up of two tetrachords placed one on top of the other. The lowest note of the first tetrachord forms an octave with the top note of the second as a frame. If you take small, large and excessive seconds as a starting point, the following (melodic) models arise:
(The notes in red indicate lead tone functions)
- a) Both tetrachords of the major scale are built according to this model. The semitone at the end has an upward tendency to move.
- b) The symmetrical structure with the semitone in the middle creates an energy flowing in both directions.
- c) This tetrachord is a reversal of model a). The direction of movement is from top to bottom.
- d) The last three models each contain an excessive second (hiatus) . Such an "unsangible" step inhibits the flow of movement. In this symmetrical tetrachord it lies in the middle and can thus be used.
- e) and f) The excessive second limits the weight of the edge tones.
All heptatonic scales made up of whole and semitones are called diatonic . Depending on the relationship between the whole and semitones, different tone sexes arise . If you want to be able to start a heptatonic scale on each of the root tones, you need a total of twelve semitones, i.e. H. every diatonic seven order is integrated into the chromatic - enharmonic twelve order.
Heptatonic scales (examples)
- The major scale
- The different minor scales (e.g. natural, harmonic, melodic minor)
- The church scales ( Doric , Phrygian , Lydian , Mixolydian , Locrian , and so on)
- The Phrygian dominant scale
- The gypsy scales
- The harmonic major scale
- The Mi- Shebach scale
- The altered scale
- The enigmatic ladder
- The early Greek aulos modes
- The ragas of Indian music
- The twelve Lü of Chinese music
- Slendro and Pélog of gamelan music on the Indonesian islands of Java and Bali
- The blue scales (see also blue notes )
- Pentatonic (i.e. five different tones)
- octatonic scales such as the diminished scale or the bebop scales