In music theory, the term scale degree refers to the position of a particular note on a scale relative to the tonic, the first and main note of the scale from which each octave is assumed to begin. Degrees are useful for indicating the size of intervals and chords and whether they are major or minor.
In the most general sense, the scale degree is the number given to each step of the scale, usually starting with 1 for tonic. Defining it like this implies that a tonic is specified. For instance, the 7-tone diatonic scale may become the major scale once the proper degree has been chosen as tonic (e.g. the C-major scale C–D–E–F–G–A–B, in which C is the tonic). If the scale has no tonic, the starting degree must be chosen arbitrarily. In set theory, for instance, the 12 degrees of the chromatic scale usually are numbered starting from C=0, the twelve pitch classes being numbered from 0 to 11.
In a more specific sense, scale degrees are given names that indicate their particular function within the scale (see table below). This definition implies a functional scale, as is the case in tonal music.
The term scale step is sometimes used synonymously with scale degree, but it may alternatively refer to the distance between two successive and adjacent scale degrees (see steps and skips). The terms "whole step" and "half step" are commonly used as interval names (though "whole scale step" or "half scale step" are not used). The number of scale degrees and the distance between them together define the scale they are in.
Major and minor scales
- by their ordinal numbers, as the first, second, third, fourth, fifth, sixth, or seventh degrees of the scale, sometimes raised or lowered;
- by Arabic numerals (1, 2, 3, 4 …), sometimes with circumflexes (, , , …);
- by Roman numerals (I, II, III, IV …);
- by the English name for their function: tonic, supertonic, mediant, subdominant, dominant, submediant, leading note (leading tone in the United States), and tonic again. These names are derived from a scheme where the tonic note is the 'centre'. Then the supertonic and subtonic are, respectively, a second above and below the tonic; the mediant and submediant are a third above and below it; and the dominant and subdominant are a fifth above and below the tonic. The word subtonic is used when the interval between it and the tonic in the upper octave is a whole step; leading note is used when that interval is a half-step.
- by their name according to the movable do solfège system: do, re, mi, fa, so(l), la, and si (or ti).
Scale degree names
|Degree||Name||Corresponding mode (major key)||Corresponding mode (minor key)||Meaning||Note (in C major)||Note (in C minor)|
|1||Tonic||Ionian||Aeolian||Tonal center, note of final resolution||C||C|
|2||Supertonic||Dorian||Locrian||One whole step above the tonic||D||D|
|3||Mediant||Phrygian||Ionian||Midway between tonic and dominant, (in minor key) root of relative major key||E||E♭|
|4||Subdominant||Lydian||Dorian||Lower dominant, same interval below tonic as dominant is above tonic||F||F|
|5||Dominant||Mixolydian||Phrygian||Second in importance to the tonic||G||G|
|6||Submediant||Aeolian||Lydian||Lower mediant, midway between tonic and subdominant, (in major key) root of relative minor key||A||A♭|
|7||Subtonic (in the natural minor scale)||Mixolydian||One whole step below tonic in natural minor scale.||B♭|
|Leading tone (in the major scale)||Locrian||One half step below tonic. Melodically strong affinity for and leads to tonic||B|
|1||Tonic (octave)||Ionian||Aeolian||Tonal center, note of final resolution||C||C|