tertiades

A tertiade is a musical chord consisting of three notes, separated by intervals of a third. The most common tertiades are triads, which are built using two thirds stacked on top of each other. For example, a C major triad consists of the notes C, E, and G, forming a root, a major third, and a perfect fifth.

Triads are the fundamental building blocks of Western harmony. They are classified by the quality of the intervals they contain, leading to four basic types: major, minor, diminished, and augmented. A major triad has a root, a major third, and a perfect fifth. A minor triad has a root, a minor third, and a perfect fifth. A diminished triad has a root, a minor third, and a diminished fifth. An augmented triad has a root, a major third, and an augmented fifth.

These basic triads can be further modified by adding additional thirds to create seventh chords, ninth chords, and so on, forming more complex tertiades. The relationships between these chords, governed by the principles of voice leading and harmonic progression, create the rich tapestry of sound found in music. The concept of tertiades is essential for understanding melody, harmony, and musical composition.