Major third

Major Third

The major third is an interval in music theory that spans four semitones, making it wider than a minor third, which spans three semitones. It is one of the basic building blocks in the construction of chords and scales, particularly within Western music. The major third is considered to be consonant, pleasant to the ear, and is central to the formation of major chords and major scales.

Definition and Characteristics

A major third is defined as an interval that is four semitones above the tonic note. In equal temperament tuning, which is the most common tuning system used in Western music, all semitones have the same frequency ratio, making the major third an easily recognizable sound. The major third can be found by starting on any note and moving up four semitones, or two whole steps.

Notation and Examples

In musical notation, a major third is often denoted by the abbreviation M3. For example, the major third above C is E, as the sequence from C to E encompasses four semitones (C-C#-D-D#-E). Similarly, the major third above G is B, and so on for other notes.

Role in Music

The major third plays a crucial role in the construction of major scales and chords. A major scale is formed by a specific sequence of intervals, starting with a major second, followed by a major third, and so on. The major third is also a critical component of a major chord, which consists of a root note, a major third, and a perfect fifth.

Harmony and Consonance

The major third is considered to be a consonant interval, meaning it is harmonically pleasing and stable. This consonance is a result of the simple integer ratios that define the frequencies of the notes in a major third, typically 4:5 in just intonation. This pleasant quality makes the major third a popular choice for creating harmonies in music.

Historical Context

The appreciation and use of the major third have evolved over time. In the Middle Ages and Renaissance, intervals such as the perfect fourth and perfect fifth were more commonly used and considered more consonant. However, by the time of the Baroque period, the major third had become an essential element of harmony, leading to the development of the tonal system that dominates Western music.

See Also

• Minor third
• Perfect fifth
• Chord (music)
• Scale (music)
• Tonic (music)