Mediant: In music theory, the mediant is the third scale degree of a diatonic scale, positioned between the tonic and the dominant.

Context and Significance

The mediant holds an important role in music composition, offering a bridge between the tonic and dominant within a scale. It adds depth and variety to harmonic progressions, often featuring in classical, jazz, and pop music. The mediant can create a sense of movement and tension, particularly when used in chord progressions or melodic lines. Its placement within the scale makes it a versatile tool for composers looking to explore key changes or enhance a piece’s emotional impact.

Historical Background

The concept of the mediant has roots in medieval music theory, where it was recognized as a pivotal scale degree. The term derives from the Latin word “medius,” meaning “middle,” reflecting its central position within the scale. Over time, the mediant became a critical element in Western music theory, especially during the Common Practice Period, where it was frequently used to modulate between keys and enrich harmonic structures in compositions by composers like Bach and Beethoven.

Examples

In Beethoven’s Symphony No. 3 (“Eroica”), the mediant plays a crucial role in the harmonic structure, providing contrast and tension. In pop music, the mediant is often used to shift emotion within a song, as seen in The Beatles’ “A Hard Day’s Night,” where it contributes to the dynamic key changes. Jazz musicians frequently use the mediant to create unexpected turns in their improvisations, adding complexity to their solos.

Related Terms

Tonic: The first scale degree, serving as the tonal center.

Dominant: The fifth scale degree, creating tension that resolves to the tonic.

Submediant: The sixth scale degree, often used in modulation.

Leading Tone: The seventh scale degree, resolving to the tonic.

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