What Is Chord Theory?

Chord theory is a small component of overall music theory, or how music is created. This approach considers how clusters of three or more notes are used to produce distinct sounds. Chords can be implemented on a wide variety of instruments, and they are present in many forms of music. Understanding the structural basics of scales, intervals, and other musical components is essential to chord theory.

Musical notes are the symbols on a sheet of music, and as such are the building blocks of chord theory. They are individual sounds that tell the musician what sound to play, and how long to play it. When three ore more notes are combined together, a chord results. They generally are heard in the background of a song, under the melody.

Chord types are another basic component of chord theory. A musician may play the notes of a chord simultaneously, creating a harmonic chord. A melodic chord, on the other hand, results when each note is played separately. Strumming a guitar is one such example. Different combinations of chords also have different names. For example, a three-note combination is known as a triad.

In part, a chord is named according to where its first note occurs on a musical staff, or diagram. A common staff consists of five lines and four spaces between the lines. Each of these areas represents a different level of sound produced, and each is usually assigned a lettered or numerical designation.

Chords may be thus named numerically or alphabetically. If the first note of a chord were to occur in the C area of the staff, for example, the chord might be known as a C chord. Numbering the areas of a staff might produce a I chord or a IV chord. In general, Roman numerals are used for these distinctions in many regions. The first note may also establish the key, or overall tone, of a piece of music.

Scales, or the overall sequence of musical notes, are the other major factor in identifying a chord. These orderings stack collections of notes together, usually in ascending or descending order along the staff. The distance between each note — or the interval — is another important consideration in the types of sounds produced in chord theory. Two main types of scales are major and minor. Major chords tend to produce a more upbeat and vibrant sound, while minor chords are more somber.

All chords may function well together, but each produces a distinct sound. Discovering the best combinations of chords and the best flow produced in different areas of a song is one of the primary talents of a gifted musician. In the music of some regions of the world, however, chords may be sparse or even completely non-existent.