Tonika ( French tonique , tonic to Greek τόνος tonos 'tension'). “In major-minor-tonal music, tonic is the root note of the key that is named after it, e.g. B. C major to C, A minor to a. The functional theory of harmony understands the tonic as the triad built on it, the main sound of the key (in C major ceg, in A minor ace). ”It is the name for the first step of a key .
The name tonic goes back to the term "l'accord tonique" ("the chord of the root or the chord with the special emphasis") invented by Jean-Philippe Rameau (1683–1764), with which this is the essential characteristic of the tonic tried to paraphrase, namely their ability to stand like a magnet in the center of all harmonic fields of tension . Therefore, the tonic is often referred to as “tonal center”.
At the latest since the introduction of functional theory , the term tonic has been a clearly defined parameter, also and especially under the aspect of forming a reference point to the two dominants ( dominant , subdominant ) and to other ladder-specific chords within the framework of a cadence . According to classical harmony theory, the tonic is usually at the beginning and at the end of a piece of music. Almost all pieces of music in classical European music have a basic key.
Treatment in classical harmony
The classical theory of harmony, in which only octaves, fifths, thirds and sixths count as consonances, allows only triads as tonic sounds . The keynote is indispensable; If the fifth, the third or both are missing, the resulting sound is interpreted as a representative of the actual tonic triad.
Treatment in modern harmony
According to the modern theory of harmony, the tonic triad can be expanded to a four-chord. In pop music, for example, the dominant is often resolved into a major tonic extended by the interval of a major sixth . In spite of this, the tonic retains its function as a consonant-sounding, tonal center. The reason for this lies in changed listening habits: The sixte ajoutée was formulated theoretically in the late Baroque music by Jean-Philippe Rameau and was still an extremely dissonant interval at that time, whereas today's listeners perceive this interval as absolutely consonant .
Depending on the type of tone or the style of music, the tonic can be supplemented with other ladder-specific tones. In jazz, for example, it is common to add a major seventh to a major tonic . Here, too, changed listening habits ensure that this actually very dissonant interval does not impair the function of the tonic as a tonal center. The extension of the tonic by the interval of a ninth is also occasionally practiced.
The expansion of the major tonic in the blues is a special case. A minor seventh is very often added here, which in this special case is not part of the major scale on which it is based, but is taken from the natural minor scale based on the root of the tonic . This practically mixes major with minor in this tonic chord. This minor seventh must not be confused with the blue note .