from Wikipedia, the free encyclopedia

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 .:

Scale with marked tetrachords

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:

Different tetrachords

(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)

Other scales

See also