Chord Music

chord, in music, is any harmonic set of pitches consisting of two or more notes that are heard as if sounding simultaneously. Chords and sequences of chords are frequently used in modern West African and Oceanic music, Western classical music, and Western popular music; yet, they are absent from the music of many other parts of the world. In tonal Western classical music, the most frequently encountered chords are triads, so called because they consist of three distinct notes: the root note, and Intervals of a third and a fifth above the root note. Other chords with more than three notes include added tone chords, extended chords and tone clusters, which are used in contemporary classical music, jazz and other genres. An ordered series of chords is called a chord progression. One example of a widely used chord progression in Western traditional music and blues is the 12 bar blues progression. Although any chord may in principle be followed by any other chord, certain patterns of chords are more common in Western music, and some patterns have been accepted as establishing the key(tonic note) in common-practice harmony–notably the movement between tonic and dominant chords. To describe this, Western music theory has developed the practice of numbering chords using Roman numerals which represent the number of diatonic steps up from the tonic note of the scale. Common ways of notating or representing chords in Western music (other than conventional staff notation) include Roman numerals, figured bass, macro symbols (sometimes used in modern musicology), and chord charts.

The English word chord derives from Middle English cord, a shortening of accord in the original sense of agreement and later, harmonious sound. A sequence of chords is known as a chord progression or harmonic progression. These are frequently used in Western music. A chord progression “aims for a definite goal” of establishing (or contradicting) a tonality founded on a key, root or tonic chord. The study of harmony involves chords and chord progressions, and the principles of connection that govern them.

Many chords are a sequence of ascending notes separated by intervals of roughly the same size. Chords can be classified into different categories by this size:

  • Tertian chords can be decomposed into a series of (major or minor) thirds. For example, the C major triad (C–E–G) is defined by a sequence of two intervals, the first (C–E) being a major third and the second (E–G) being a minor third. Most common chords are tertian.
  • Secundal chords can be decomposed into a series of (major or minor) seconds. For example, the chord C–D–E is a series of seconds, containing a major second (C–D) and a minor second (D–E).
  • Quartal chords can be decomposed into a series of (perfect or augmented) fourths. Quartal harmony normally works with a combination of perfect and augmented fourths. Diminished fourths are enharmonically equivalent to major thirds, so they are uncommon.[36] For example, the chord C–F–B is a series of fourths, containing a perfect fourth (C–F) and an augmented fourth/tritone (F–B).