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The basic tone is the fundamental tone of a scale , an interval , a chord , an acoustic sound or the tuning of a musical instrument . In relation to tonal musical sections or pieces of music, the basic tone is synonymous with the terms tonic or tonal center , e.g. B. the c in C major.

Root note of a scale

Major scale above the root C. The brackets indicate the semitone steps.

The basic tone of a scale is the tone that gives the key its name, such as C major or A minor. Usually the scale is given in ascending order from its root note. An exception are the plagal church modes (e.g. Hypodoric), in which the keynote is not at the beginning but in the middle of the scale.

In Gregorian chant , the keynote was identical to the final note of a melody and was therefore also referred to as “ finalis ”.

Root note of an interval

In older literature, the fundamental tone of an interval is simply the lower of the two tones involved. Interval fundamental tones in the real sense, namely a dominant main tone, were first introduced into music theory by Paul Hindemith in his 1937 Instruction in Tone Theory. Hindemith relies on the phenomenon of combination tones , which in certain cases ensure that one of the two interval tones is tonally amplified and thus exceeds the other in weight. For example, the lower note of a fifth and the upper note of a fourth are amplified. Correspondingly, the lower note of the major third and the upper note of the minor sixth turns out to be the fundamental tone. With the other intervals, however, the combination tones do not give a clear result, since they no longer coincide with one of the two interval tones. Here Hindemith assigns the fundamental tones of the interval according to more pragmatic criteria.

Root note of a chord

Basic position and inverse forms of a C major triad. The keynote (red) remains the same.

In figured bass and partly in harmony as well, the root note of a chord is the lowest note of its basic position, in which it consists of thirds stacked on top of each other . While identical in the basic position basic and bass, with changes latter inversion of the chord, the tone remains the same while.

Step and function theory

The equation of the root note with the bass note of the basic position is only valid without restriction in the theory of degrees . In the function theory developed later, the fundamental tone of a chord is understood to be that which corresponds to its harmonic function, which can result in deviations from the theory of degrees. So you write z. B. to the chord b-d'-f 'in C major because of its tendency to resolve into the tonic a dominant function. It is viewed as a shortened dominant seventh chord and assigned the root g, although it does not sound. While in level theory the chord belongs to level VII, functional theory assigns it to level 5 (dominant).

Another example of the different interpretation of a chord is the sixte-ajoutée chord fa-c'-d '. The degree theory interprets it as the first inversion of the seventh chord of the second degree with the fundamental note d, the functional theory as a subdominant sound with the fundamental note f.

Determination of the root note according to Hindemith

Since traditional harmony theory has problems with the interpretation of chords that cannot be traced back to the principle of thirds, Hindemith sees it as too narrow a system of sound determination and develops a new chord theory that can be applied to all conceivable sounds. The root of a chord is then identified with the root of the “best” interval it contains. The "best" interval is the one with the highest degree of consonance , that is, the one that is furthest in front in the series of intervals (fifth, fourth, major third, minor sixth ...) arranged in decreasing order of sound value. So if the chord contains a fifth, which is often the case, its lowest note is the root note; if two fifths appear in the chord, the lower fifth determines the root note because of its greater weight.

In simple cases, step theory, function theory and Hindemith's method give the same result. All three see z. B. in the C major triad the c as the root note. In other cases, however, there may be differences in interpretation. In C major, for example, the half-diminished seventh chord h-d'-f'-a 'is interpreted by degree theory as the seventh chord of the seventh degree (root h), by function theory as a shortened dominant seventh chord (root g), and determined by Hindemith the root note from the fifth d'-a 'to d'.

Root note of a sound

Notation of the first 16 tones of the partial tone series above the root C. The numbers and arrows indicate the deviation of the partial tones from the noted pitches in cents .

In the acoustic sense, a single tone is usually not a sine tone , but a complex sound composed of such . Its fundamental frequency is also called the fundamental tone and in most cases corresponds to the actual pitch perceived . More rarely there is the acoustic phenomenon that the fundamental frequency is completely absent in a sound and this is nevertheless perceived at the level of the missing fundamental frequency ('Missing Fundamental', residual tone ).

The overtone series of a fundamental tone generally not only determines the timbre , but also has a direct influence on the timbre of the perceived tone due to its composition (e.g. with regard to the differences in the strength of the individual overtones).

If the overtones are rather weak, one speaks of a "fundamental" sound. The powers of two of the fundamental frequency (these correspond to the partial tones 2, 4, 8 and 16) of a tone always result in their octaves.

Root note for musical instruments

The fundamental tone of a brass instrument is the deepest natural tone that the instrument can produce (without using valves or slides). It determines the basic tuning of the instrument. For transposing instruments , this note is notated as c .

With some woodwind instruments , for example almost all recorders , the keynote denotes the lowest playable note. With him all tone holes are closed, so the vibrating column of air is about the length of the entire instrument.

In the case of string instruments with a fingerboard (e.g. violin, guitar), the tone of an "empty" (unhandled) string is sometimes referred to as its root.


Individual evidence

  1. z. B. Oscar Kolbe: Concise figured bass theory. 2nd Edition. Breitkopf and Härtel, Leipzig 1872, p. 14, ( online ).
  2. “In the basso continuo theory, the root note is the note which is the lowest when the chord is built up by thirds, e.g. B. c in ceg or g in ghdf If the root is in the bass, the chord appears in the foundation, if one of the other notes is in the bass, then you have an inversion before you. "-" keynote ". In: Hugo Riemann: Music Lexicon. 10th edition, edited by Alfred Einstein . Hesse, Berlin 1922, p. 478.