Major and minor in the context of "Modality (music)"

In music theory, the term mode or modus is used in a number of distinct senses, depending on context.

Its most common use may be described as a type of musical scale coupled with a set of characteristic melodic and harmonic behaviors. It is applied to major and minor keys as well as the seven diatonic modes (including the former as Ionian and Aeolian) which are defined by their starting note or tonic. (Olivier Messiaen's modes of limited transposition are strictly a scale type.) Related to the diatonic modes are the eight church modes or Gregorian modes, in which authentic and plagal forms of scales are distinguished by ambitus and tenor or reciting tone. Although both diatonic and Gregorian modes borrow terminology from ancient Greece, the Greek tonoi do not otherwise resemble their medieval/modern counterparts.

In music, the tonic is the first note scale degree () of the diatonic scale (the first note of a scale) and the tonal center or final resolution tone that is commonly used in the final cadence in tonal (musical key-based) classical music, popular music, and traditional music. In the movable do solfège system, the tonic note is sung as do. More generally, the tonic is the note upon which all other notes of a piece are hierarchically referenced. Scales are named after their tonics: for instance, the tonic of the C major scale is the note C.

The triad formed on the tonic note, the tonic chord, is thus the most significant chord in these styles of music. In Roman numeral analysis, the tonic chord is typically symbolized by the Roman numeral "I" if it is major and by "i" if it is minor.

In music, the fifth factor of a chord is the note or pitch that is the fifth scale degree, counting the root or tonal center. When the fifth is the bass note, or lowest note, of the expressed chord, the chord is in second inversion Play.

Conventionally, the fifth is second in importance to the root, with the fifth being perfect in all primary triads (I, IV, V and i, iv, v). In jazz chords and theory however, the fifth is often omitted, or assumed, in preference for the chord quality determining third and chord extensions and additions.

There is a long tradition in classical music of writing music in sets of pieces that cover all the major and minor keys of the chromatic scale. These sets typically consist of 24 pieces, one for each of the major and minor keys (sets that comprise all the enharmonic variants include 30 pieces).

Examples include Johann Sebastian Bach's The Well-Tempered Clavier and Frédéric Chopin's 24 Preludes, Op. 28. Such sets are often organized as preludes and fugues or designated as preludes or études. Some composers have restricted their sets to cover only the 12 major keys or the 12 minor keys; or only the flat keys (Franz Liszt's Transcendental Études) or the sharp keys (Sergei Lyapunov's Op. 11 set). In yet another type, a single piece may progressively modulate through a set of tonalities, as occurs in Ludwig van Beethoven's 2 Preludes through all the Major Keys, Op. 39.

In music theory, a neutral interval in 24 TET (including extensions), (but also known as a submajor interval, or as a superminor interval, in Just Intonation), is an interval that is neither major nor minor, but is, instead, in-between them.

In 12 TET, these intervals are a quarter tone sharper than minor intervals and a quarter tone flatter than major intervals. For example, the minor third is tuned at 300 ¢, while the major third is a semitone (100 ¢) sharper (400 ¢), and so the neutral third lies between them at 350 ¢.

Jazz harmony is the theory and practice of how chords are used in jazz music. While jazz bears certain similarities to other practices in the tradition of Western harmony, such as many chord progressions and the incorporation of the major and minor scales as a basis for chordal construction, other characteristics such as modality, syntax and phrase structure separate it from Western tradition. In jazz, chords are often arranged vertically in major or minor thirds, although stacked fourths are also quite common. Also, jazz music tends to favor certain harmonic progressions and includes the addition of tensions, intervals such as 9ths, 11ths, and 13ths to chords. Additionally, scales unique to style are used as the basis of many harmonic elements found in jazz. Jazz harmony is notable for the use of seventh chords as the basic harmonic unit more often than triads, as in classical music. In the words of Robert Rawlins and Nor Eddine Bahha, "7th chords provide the building blocks of jazz harmony."

The piano and guitar are the two instruments that typically provide harmony for a jazz group. Players of these instruments deal with harmony in a real-time, flowing improvisational context as a matter of course. This is one of the greatest challenges in jazz.