What is an altered chord? In the realm of music theory, an altered chord is a type of chord that adds a sharpened or flattened note to the diatonic scale, creating a unique and expressive sound. Unlike traditional chords that follow the standard major or minor scale, altered chords introduce a sense of tension and dissonance, making them an essential element in various musical styles, including jazz, rock, and fusion. This article aims to delve into the concept of altered chords, their construction, and their applications in music.
Altered chords are derived from the diatonic scale, which consists of seven notes. The basic structure of a diatonic chord involves selecting three or more notes from this scale to create a harmonious combination. However, in the case of altered chords, one or more of these notes are modified to create a distinctive sound. The alterations can be applied to any note within the diatonic scale, and there are four primary types of alterations: sharp, flat, augmented, and diminished.
To understand altered chords better, let’s consider an example in the key of C major. The diatonic scale in this key is C, D, E, F, G, A, and B. A standard C major chord consists of the notes C, E, and G. To create an altered chord, we can alter one or more of these notes. For instance, a C major seventh sharp five chord (C75) is formed by adding the note G (a sharp five) to the standard C major chord. This addition of the sharp five creates a more complex and dissonant sound, often used to introduce tension and resolution in a musical piece.
Another example is the C major seventh flat nine chord (C7b9), which adds the note Bb (a flat nine) to the C major chord. This alteration results in a sound that is both dissonant and rich, often employed in jazz music to create a sense of anticipation and resolution.
Altered chords can also be constructed using the augmented and diminished alterations. An augmented fifth is created by sharpening the fifth note of a diatonic chord, while a diminished fifth is achieved by flattening it. These alterations add a sense of tension and instability to the chord, making them suitable for creating dramatic and expressive passages in music.
In conclusion, altered chords are a vital component of modern music theory, offering musicians a wide range of expressive possibilities. By understanding the construction and application of altered chords, composers and performers can create rich, dynamic, and emotionally charged music. Whether in jazz, rock, or fusion, altered chords provide a unique sound that can transform a simple melody into a powerful and memorable composition.
