# Tonic (music)

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Tonic (I) in ii-V-I turnaround on C, found at the end of the circle progression
Major seventh chord on C  . I7 or tonic seventh chord in C major.[1]
Minor-minor (i7) seventh chord on C in natural minor.[2]
Tonic minor 6/9 chord on C, featuring the raised sixth degree of the ascending melodic minor.[3]

In music, the tonic is the first scale degree of the diatonic scale and the tonal center or final resolution tone.[4] The triad formed on the tonic note, the tonic chord, is thus the most significant chord. More generally, the tonic is the pitch upon which all other pitches of a piece are hierarchically referenced. Scales are named after their tonics, thus the tonic of the scale of C is the note C.

In very much conventionally tonal music, harmonic analysis will reveal a broad prevalence of the primary (often triadic) harmonies: tonic, dominant, and subdominant (i.e., I and its chief auxiliaries a 5th removed), and especially the first two of these.

—Berry (1976)[5]

The tonic is often confused with the root, which is the reference note of a chord, rather than that of the scale. It is also represented with the Roman numeral I.

## Importance and function

In western European tonal music of the 18th and 19th centuries, the tonic center was the most important of all the different tone centers which a composer used in a piece of music, with most pieces beginning and ending on the tonic, usually modulating to the dominant (the fifth above the tonic, or the fourth note down from the tonic) in between.

The tonic remains the same in both major and minor keys, compared to other scale degrees such as the third degree (mediant) and the sixth degree (submediant). For example, in both C major and C minor, the tonic is C. Keys that share key signatures (i.e. relative keys) however have different tonics. For example, C major and A minor share a key signature that feature no sharps or flats despite containing different tonic pitches, C and A, respectively.

{{safesubst:#invoke:anchor|main}}Tonic may be reserved exclusively for use in tonal contexts while tonal center and/or pitch center may be used in post- and atonal music: "For purposes of non-tonal centric music, it might be a good idea to have the term 'tone center' refer to the more general class of which 'tonics' (or tone centers in tonal contexts) could be regarded as a subclass."[6] Thus a pitch center may function referentially or contextually in an atonal context, often acting as axis or line of symmetry in an interval cycle.[7] Pitch centricity was coined by Arthur Berger in his "Problems of Pitch Organization in Stravinsky".[8]

The tonic diatonic function includes four separate activities or roles as the principal goal tone, initiating event, generator of other tones, and the stable center neutralizing the tension between dominant and subdominant.

## Other scale degrees

Circle progression on C goes through tonic, subdominant, leading-tone, mediant, submediant, supertonic, and dominant before returning to tonic: I-IV-viio-iii-vi-ii-V-I

After tonic, the names of the remaining scale degrees (of a diatonic scale) in order are as follows:
supertonic — second scale degree (the scale degree immediately "above" the tonic);
mediant — third scale degree (the "middle" note of the tonic triad);
subdominant — fourth scale degree (a fifth "below" the tonic);
dominant — fifth scale degree (the most "pronounced" harmonic note after the tonic);
submediant — sixth scale degree (the "middle" note of the subdominant triad);
leading tone (or leading note) — seventh scale degree (the scale degree that "leads" to the tonic, this is also referred to as subtonic);
subtonic - also seventh scale degree, but applying to the lowered 7th found in the natural minor scale.