Thaat

Hindustani heptatonic theory additionally stipulates that the second, third, sixth and


seventh degrees of heptatonic scale forms (septak) are also allowed only two


inflections each, in this case, one natural position, and one lowered (komal) position.


Arithmetically this produces 25, or thirty-two, possibilities, but Hindustani theory, in


contradistinction to Carnatic theory, excludes scale forms not commonly used.

Heptonia Tertia

The last group of seven note tone/semitone scales are known as Heptonia Tertia and


consist of scales with two adjacent semitones which amounts to a whole-tone scale


but with an additional note somewhere in its sequence e.g. b c d e f# g# a#.

Heptonia Prima and Secunda

Heptonia Prima and Secunda
The rather unwieldy name of Heptonia Prima and Heptonia Secunda are given to the


various seven-note scales which can be formed using tones and semitones but


without two semi-tones appearing in succession. Some are more theoretical than


others. They are


Heptonia Prima
Beginning on keynote A and working up the notes of the 'natural minor' scale


(A,B,C,D,E,F,G,A), the seven modes are:


Aeolian mode (natural minor)


Locrian mode


Ionian Mode (major)


Dorian Mode


Phrygian Mode


Lydian Mode


Mixolydian Mode


It may be noted that the Dorian is exactly the same descending as ascending. The


less common series is


Heptonia Secunda
The difference between this and the diatonic modes is that they have two and three


tones between each semitone, while these latter modes have one and four. These


are sometimes called modes of the melodic ascending minor since that is the most


commonly used scale of this type, but other modes can be produced by starting on


the different scale notes in turn. Thus starting on keynote A as above and following


the notes of the ascending melodic minor (A,B,C,D,E,F#,G#) yields these seven


modes:


'Melodic ascending minor'


'Phrygian raised sixth' combines the Phrygian flat second and Dorian raised sixth


'Lydian raised fifth' combines the Lydian fourth with a raised fifth


'Acoustic' or 'Lydian-Myxolydian' Scale So-called because close to the scale built


on natural overtones and combines Lydian raised fourth with Myxolydian flat


seventh


'Major minor' scale Like natural minor (aeolian) but with a major third


'Half diminished' or 'Locrian sharp 2' scale This is like the Locrian with a raised


second


'Altered scale' Like Locrian with flat fourth


These modes are more awkward to use than those of the diatonic scales due to the


four tones in a row yielding augmented intervals on one hand while the one tone


between two semitones gives rise to diminished intervals on the other. For example,


the last two modes listed above both have 'Locrian' diminished triads built on their


tonics given them unstable tonality while the fourth mode not only has an augmented


fourth a la the Lydian mode but also an augmented fifth making the dominant and


subdominant unusable.

Harmonic minor scale

The harmonic minor scale is so called because in tonal music of the “common


practice period” (from approximately 1600 to approximately 1900) chords or


harmonies are more commonly derived from it than from either the natural minor


scale or the melodic minor scale. The augmented second between its sixth degree


and its raised (“leading tone”) seventh degree, usually traditionally considered


undesirable, is easily avoided by distributing these pitches among voices. In the


chord progression, D F A(flat), B F G, C E(flat) G, (ii0, V7, i in C minor) for example,


the Ab in the upper voice never ascends to B, and the B in the lower voice never


descends to Ab.

Melodic minor scale

In traditional classical theory the melodic minor scale has two forms, as noted


above, an ascending form and a descending form. Although each of these forms of


itself comprises seven pitches, together they comprise nine, which might seem to


call into question the scale’s status as a heptatonic scale. In certain twentieth-century


music, however, it became common systematically to use the ascending form for


both ascending and descending passages. Such a use has been notably ascribed to


the works of Bela Bartok and to bop and post-bop jazz practice. The traditional


descending form of the melodic minor scale is equivalent to the natural minor scale in


both pitch collection (which is diatonic) and tonal center.

Diatonic scale

The term diatonic scale refers to a pitch collection and does not imply any particular


tonal center or note of especial emphasis. It is in this respect different from the term


major scale, which does imply a tonal center.

Heptatonic scale

A heptatonic scale is a musical scale with seven pitches per octave. Among the


most famous of these are the diatonic scale, C D E F G A B C; the melodic minor


scale, C D E(flat) F G A B C ascending, C B(flat) A(flat) G F E(flat) D C descending;


the harmonic minor scale, C D E(flat) F G A(flat) B C; and a scale variously known


as the Byzantine, Hungarian, gypsy, or Egyptian scale, C D E(flat) F(sharp) G A(flat)


B C. South Indian (Carnatic music) classical theory postulates seventy-two


melakarta, seven-tone scale types, whereas Hindustani classical music postulates


twelve or ten (depending on the theorist) seven-tone scale types collectively called


thaat.

SCALES

In music, a scale is a group of musical notes collected in ascending and descending order, that provides material for or is used to conveniently represent part or all of a musical work including melody and/or harmony. Scales are ordered in pitch or pitch class, with their ordering providing a measure of musical distance.


Scales are typically listed from low to high. Most scales are octave-repeating, meaning their pattern of notes is the same in every octave. An octave-repeating scale can be represented as a circular arrangement of pitch classes, ordered by increasing (or decreasing) pitch class. For instance, the increasing C major scale is, C-D-E-F-G-A-B-[C], with the bracket indicating that the last note is an octave higher than the first note. Or C-B-A-G-F-E-D-[C], with the bracket indicating an octave lower than the first note in the scale.