A chord is a combination of three or more notes played simultaneously. The notes in a chord are typically arranged in a specific order, called a chord voicing, which determines the overall sound of the chord.

The three main types of chords are major, minor, and diminished. Major chords have a bright and cheerful sound, minor chords have a sad and somber sound, and diminished chords have a tense and dissonant sound.

Chords are constructed by stacking thirds. The first note of the chord is called the root, the second note is called the third, and the third note is called the fifth. The interval between the root and the third is a major third or a minor third, and the interval between the third and the fifth is a perfect fifth.

The main difference between a major chord and a minor chord is the interval between the root and the third. In a major chord, the interval is a major third, which is four half steps. In a minor chord, the interval is a minor third, which is three half steps.

A diminished chord is a chord with a flat third and a flat fifth. The interval between the root and the third is a minor third, and the interval between the third and the fifth is a diminished fifth, which is two half steps.

The primary function of a chord in music is to provide harmony. Chords create a sense of stability and movement in a piece of music by providing a foundation for the melody and rhythm.

A chord progression is a series of chords played in a specific order. Chord progressions are used to create a sense of movement and direction in a piece of music.

The most common chord progression in Western music is the I-IV-V progression. This progression is often used in popular music, rock music, and jazz music.

A cadence is a chord progression that ends on a tonic chord. Cadences are used to create a sense of finality and resolution in a piece of music.

The three main types of cadences are authentic, half, and deceptive. Authentic cadences end on the tonic chord, half cadences end on the dominant chord, and deceptive cadences end on a chord other than the tonic or dominant chord.

A tonic chord is the chord that is built on the root note of a key. The tonic chord is the most stable chord in a key and is often used to end a piece of music.

A dominant chord is a chord that is built on the fifth note of a key. Dominant chords are often used to create a sense of tension and movement in a piece of music.

A subdominant chord is a chord that is built on the fourth note of a key. Subdominant chords are often used to create a sense of stability and movement in a piece of music.

A mediant chord is a chord that is built on the third note of a key. Mediant chords are often used to create a sense of color and variety in a piece of music.

A leading tone chord is a chord that is built on the seventh note of a key. Leading tone chords are often used to create a sense of tension and movement in a piece of music.