# Third (music)

Diatonic intervals
Prime
second
third
fourth
fifth
sixth
seventh
octave
none
decime
undezime
duodecime
tredezime
semitone / whole tone
Special intervals
Microinterval
Comma
Diësis
Limma
Apotome
Ditone Tritone
Wolf
fifth
Natural septime
units
Cent
Millioctave
Octave
Savart

Third (from Latin tertia : "the third") describes the interval in music that spans three levels of a diatonic scale .

Example : Scale section from c '' to e '' - major third c '' e '' one after the other - major third c '' e '' at the same time, then with a minor third c '' es ''.

In a narrower sense, the third is also the third level of the respective scale. The more precise term for this is third tone .

As an interval, a minor third comprises a total of three, a major third four semitone steps (diminished and excessive thirds see below). The third is the complementary interval to the sixth .

## variants

The third can appear in four variants.

The major third (4 semitones) and the minor third (3 semitones), which have a frequency ratio of 5: 4 and 6: 5 in the pure tuning , are very common because they are characteristic of the major-minor system .

Major third , called the major third as a pitch :

Minor third , called a minor third as a pitch :

The excessive third (5 semitones) and the diminished third (2 semitones) are rarer. You need pitches from different scales of the circle of
fifths .

Excessive third . In equal tuning, the major third is equal to the fourth . In a pure mood - like here - the difference can be 41 cents :

Diminished third . In equal tuning, the minor third is equal to the major second .

In the following example of the use of the Neapolitan sixth chord , the tone sequence b-g
sharp occurs in the soprano part. The frequency ratio of this diminished third in pure tuning is (16/15) × (16/15) = 1.137. In the cent measure this corresponds to 223.5 cents. In contrast, the major second is 182.4 cents or 203.9 cents in pure tuning (small or large whole tone), and 200 cents in equal tuning. For a good sound of this cadenza , if possible (e.g. with a vocal or string ensemble), the notes B flat and G sharp should be intonated appropriately by ear .

interval Semitones Examples Reversal interval
(a) major third 4 (2 whole tones) C - E , F - A
" Wake up, the rooster crowed"
small sixth
(b) minor third 3 (1 whole step + 1 semitone) C-It , A - C , E - G
"An Vo gel wanted to be married" (up)
"Ku ckuck calls's out of the woods" (down)
major sixth
(c) excessive third 5 (1 whole tone + 1 hiatus ) C - ice , As - Cis , Ces - E diminished sixth
(d) diminished third 2 (2 semitones) Gis-B , Ais-C , C-Eses , cis-It excessive sixth

In connection with the partial tones , e.g. B. in organ registers , the 5th partial is called the third. This third has a frequency ratio of 5: 4 to the next lower octave. The term minor third for the 19th partial tone, which has a frequency ratio of 19:16 to the next lower octave, is rare in this context. (For comparison: equal minor third: 300 cents , pure minor third (6/5): 315 cents, “ minor third ” related to the 19th partial tone (19/16): 298 cents.) The 19th partial tone also plays one more psychologically Role.

## Mood

The exact frequency ratio of the third is decided by the respective musical tuning system . In addition to the above-mentioned thirds, which ignore the tuning system, the following should be mentioned:

Surname Frequency ratio Cent value
Pythagorean third 81 : 64 407.82 cents
Major third of the same order ${\ displaystyle {\ sqrt [{3}] {2}}}$ : 1 400 cents
Pure major third 5 : 4 386.31 cents
Pure minor third 6 : 5 315.64 cents
Equal minor third ${\ displaystyle {\ sqrt [{4}] {2}}}$ : 1 300 cents
19th octave natural tone 19 : 16 297.51 cents

“Equal” thirds mean the thirds in equal tuning .

In equal tuning (e.g. on a piano ), major thirds are always a little too big, minor thirds a little too small compared to the pure intervals according to the table above. These differences are greatest in the thirds - together with the sixths as complementary intervals - of all intervals (see e.g. the table under Equal Tuning ). If the mood of individual tones can be influenced (e.g. in singing or on a string instrument) and if the intervals of a chord are to sound pure, the respective third scale step must be intonated a little lower as the “major third” and a little higher as the “minor third” .

## Individual evidence

1. M. Honegger, G. Massenkeil (Ed.): Das große Lexikon der Musik Volume 8, Freiburg: Herder 1987, ISBN 3-451-22921-8 , page 114
2. ^ Metzler-Sachlexikon Musik , Stuttgart: Metzler 1978. ISBN 3-476-01544-0 , page 1049
3. ^ HJ Moser: Allgemeine Musiklehre , 3rd edition, Verlag de Gruyter 1968, page 42
4. ^ Walter Opp: Handbuch Kirchenmusik , Volume 1, Merseburger 2001, pages 216, 225, 235. ISBN 3-87537-281-6
5. ^ Wolfgang Auhagen, Claudia Bullerjahn, Holger Höge: Musical memory and musical learning . 2009, ISBN 978-3-8409-2242-8 , pp. 107 ( preview in Google Book search).