Scale Degrees & Cadences

Tonic (I): The tonic is the first scale degree and serves as the home or resting point in a musical key. It has a stable and resolved quality and is often used to begin and end melodies and chord progressions. It provides a sense of resolution and tonal center.

Supertonic (ii): The supertonic is the second scale degree. It typically serves as a chord that adds harmonic interest and movement but still has some tension. In a major key, the ii chord is usually a minor chord.

Mediant (iii): The mediant is the third scale degree. It’s often used to transition between other chords, creating harmonic motion. In a major key, the iii chord is typically a minor chord.

Subdominant (IV): The subdominant is the fourth scale degree. It has a harmonically stable quality and is commonly used in chord progressions to move away from the tonic and create a sense of tension and anticipation, preparing for the dominant.

Dominant (V): The dominant is the fifth scale degree. It’s one of the most important and powerful chords in music. It has a strong, unresolved quality, and its primary function is to create tension that leads back to the tonic chord, often through a V-I cadence.

Submediant (vi): The submediant is the sixth scale degree. It’s typically a minor chord in a major key and can provide a contrasting, softer character compared to the dominant. It’s often used to create variation and emotion in chord progressions.

Leading Tone (vii°): The leading tone is the seventh scale degree. It has a strong desire to resolve upward to the tonic. In a major key, the vii° chord is typically a diminished chord. Its primary function is to create tension and lead to the tonic, often through a vii°-I or vii°-I6 progression.

These scale degrees, in combination with one another, create the harmonic and melodic structure of a piece of music. They establish a tonal center (the tonic) and create tension and release as chords and melodies move through the scale. Understanding these functions is essential for composers, arrangers, and musicians to create effective and expressive music.

Cadences are musical events that signify the end of a musical phrase, section, or piece. They provide a sense of closure and resolution to the music. Cadences are often described in terms of the scale degrees they involve. Here are some common cadences and their descriptions in accordance with scale degrees:

Authentic Cadence:

In a major key: Typically involves the dominant (V) moving to the tonic (I).
In a minor key: Involves the dominant (V) moving to the tonic (i).
Example in C major: G (V) to C (I).
The authentic cadence is the strongest and most conclusive of all cadences, providing a sense of finality and resolution.

Plagal Cadence:

In a major key: Involves the subdominant (IV) moving to the tonic (I).
In a minor key: Involves the subdominant (IV) moving to the tonic (i).
Example in C major: F (IV) to C (I).
The plagal cadence is often referred to as the “Amen” cadence and has a gentler, more peaceful quality compared to the authentic cadence.

Half Cadence:

Typically involves the dominant (V) chord ending a phrase but not resolving to the tonic. It often stops at the dominant.
Example in C major: G (V) followed by a pause or a chord other than C.
The half cadence provides a sense of incompleteness or suspension, as it leaves the listener expecting further resolution.

Deceptive Cadence:

Often involves the dominant (V) chord moving to a chord other than the expected tonic (I or i). Commonly, it moves to the vi chord or another unexpected chord.
Example in C major: G (V) to A minor (vi) instead of C (I).
The deceptive cadence creates surprise and tension by deviating from the expected resolution to the tonic.

These are some of the most common cadences in Western music, and they play a crucial role in shaping the musical structure and emotional impact of a composition. Understanding how different scale degrees interact in these cadences helps composers and musicians create specific moods and effects in their music.