Scale degrees describe the position and role of each note within a scale. In Western music theory, scale degrees are not just labels. They define how pitches behave, how melodies move, and how harmony functions within a key.
Understanding scale degrees is essential for analyzing melody, harmony, and tonal structure in both major and minor keys.
What Are Scale Degrees
A scale degree is the name given to each step of a scale, counted from the tonic.
In a seven-note diatonic scale, the degrees are numbered one through seven. Each degree has a traditional name that reflects its functional relationship to the tonic.
These names are consistent across keys and scale types.
The Seven Scale Degrees
Tonic (1)
The tonic is the central pitch of a key. It functions as the point of rest and resolution.
Melodic lines often begin or end on the tonic, and harmonic progressions tend to resolve toward it.
Supertonic (2)
The supertonic lies one step above the tonic.
It functions as a passing or preparatory tone and frequently leads toward dominant harmony. In melody, it often moves stepwise toward either the tonic or mediant.
Mediant (3)
The mediant defines the quality of the scale.
In major keys, it forms a major third above the tonic. In minor keys, it forms a minor third. This difference strongly affects the overall character of the key.
Subdominant (4)
The subdominant lies a perfect fourth above the tonic.
It functions as a point of harmonic departure, often leading away from the tonic and toward dominant tension. In melody, it creates gentle instability that encourages motion.
Dominant (5)
The dominant is the most important scale degree after the tonic.
It lies a perfect fifth above the tonic and creates strong tension that resolves back to the tonic. Dominant harmony and melodic emphasis on this degree are central to tonal music.
Submediant (6)
The submediant lies a sixth above the tonic.
In major keys, it often functions as a contrasting or resting tone. In minor keys, its alteration plays a major role in distinguishing between natural, harmonic, and melodic minor.
The submediant is also the tonic of the relative minor key.
Leading Tone or Subtonic (7)
The seventh scale degree depends on its distance from the tonic.
A leading tone lies a half step below the tonic and resolves upward.
A subtonic lies a whole step below the tonic and lacks strong resolution.
Major keys and harmonic or melodic minor use a leading tone. Natural minor uses a subtonic.
Scale Degrees in Major and Minor Keys
While scale degree names remain the same, their behavior changes between major and minor systems.
Key differences include:
lowered third in minor
variable sixth and seventh in minor
weaker dominant function without a leading tone
These differences explain why minor keys use multiple scale forms.
Functional Tendencies of Scale Degrees
Scale degrees have natural tendencies based on interval relationships.
Common tendencies:
leading tone resolves to tonic
dominant moves toward tonic
subdominant moves toward dominant
mediant and submediant often act as color tones
These tendencies guide melodic writing and harmonic progression.
Scale Degrees and Harmony
Chords built on scale degrees inherit their function.
For example:
tonic harmony stabilizes
dominant harmony creates tension
predominant harmony prepares the dominant
Roman numeral analysis is based entirely on scale degrees and their functions.
Scale Degrees and Melody
In melody, scale degrees shape phrasing and direction.
Strong scale degrees often appear on accented beats or phrase endings. Weaker degrees fill in motion and create flow.
Melodic emphasis on tonic and dominant reinforces key perception.
