Mediant is an important concept in music theory that refers to the third degree of a diatonic scale. It plays a crucial role in determining the harmony of a piece, as well as its overall tonality and mood.

What Is Mediant?

The mediant is the third note of a diatonic scale, counting from the tonic (the first note). In other words, if you were to play a C major scale (C-D-E-F-G-A-B), the mediant would be E.

Harmony and Chords

The mediant is an important note in determining the harmony of a piece. In Western music, chords are built on top of each note of a diatonic scale. For example, if we play a C major chord (C-E-G), we can see that it includes the tonic (C), the mediant (E), and the dominant (G) notes of the C major scale.

In fact, chords built on top of the tonic and mediant notes are often considered to be closely related in terms of harmony. For example, in C major, both the C major chord and E minor chord (which includes the mediant) share two out of three notes: C and E. This creates a sense of stability and coherence within a piece.

Tonality

The mediant also plays an important role in determining the tonality or key of a piece. In Western music, there are two main types of scales: major and minor. The mediant is particularly significant in minor scales, where it determines whether the scale is natural minor or harmonic minor.

For example, if we take an A natural minor scale (A-B-C-D-E-F-G), its mediant would be C. However, if we raise the seventh note by one half step (to create A harmonic minor: A-B-C-D-E-F-G#), the mediant becomes C#. This change creates a more dramatic and intense sound, which is often used in classical and film music.

Mood and Emotion

Finally, the mediant also plays a role in creating the overall mood and emotion of a piece. In Western music theory, major keys are often associated with happiness, brightness, and positivity, while minor keys are associated with sadness, darkness, and introspection.

The mediant can add to this emotional impact by either reinforcing or subverting these expectations. For example, if we take a piece in C major and use the E minor chord (which includes the mediant) at a key moment, it can create a sense of tension or melancholy within an otherwise happy piece.

Conclusion

In conclusion, the mediant is an important concept in music theory that plays a crucial role in determining harmony, tonality, and emotion within a piece. By understanding the significance of this note within a diatonic scale, we can gain a deeper appreciation for the complexity and beauty of Western music.