The Mixolydian scale is one of the seven musical modes, characterized by its major tonality with a bluesy, slightly unsettled quality due to its lowered seventh degree. It's widely used in various music genres, including rock, blues, jazz, and classical music.

Construction:

The Mixolydian scale is built using the following interval pattern:

• Whole step

• Whole step

• Half step

• Whole step

• Whole step

• Half step

• Whole step

In G Mixolydian, it would be:

• G (root)

• A (whole step)

• B (whole step)

• C (half step)

• D (whole step)

• E (whole step)

• F (half step)

• G (octave)

Features:

• Major tonality: The Mixolydian mode has a major tonality, characterized by a major third (between the root and the third degree).

• Lowered seventh degree: The defining feature of the Mixolydian mode is its flat seventh degree (compared to the major scale), which gives the scale a slightly bluesy, dominant sound.

Chord Construction:

• Tonic chord (I): G major (G, B, D)

• Supertonic chord (ii): A minor (A, C, E)

• Mediant chord (iii): B diminished (B, D, F)

• Subdominant chord (IV): C major (C, E, G)

• Dominant chord (v): D minor (D, F, A)

• Submediant chord (vi): E minor (E, G, B)

• Subtonic chord (VII): F major (F, A, C)

Usage:

• Blues and Rock: The Mixolydian mode is a staple in blues and rock music, especially for crafting guitar solos and riffs. The flattened seventh creates the characteristic "dominant" sound found in many rock and blues progressions.

• Jazz: In jazz, the Mixolydian mode is often used for improvisation over dominant seventh chords, providing a balance between major and minor tonalities.

• Folk Music: The mode is also common in various folk traditions, giving a lively and somewhat rustic feel to melodies.

The Mixolydian scale is versatile and often used to create a sense of movement and groove, especially in music that leans on dominant harmonies and a blend of major and minor tonalities.