The modes can be arranged in the following sequence, where each mode has one more shortened interval in its scale than the one preceding it.
| mode | Intervals in the modal scales | ||||||
|---|---|---|---|---|---|---|---|
| prime | second | third | fourth | fifth | sixth | seventh | |
| Lydian IV | perfect | Major | Major | Augmented | Perfect | Major | Major |
| Ionian I | perfect | Major | Major | perfect | Perfect | Major | Major |
| Mixolydian V | perfect | Major | Major | perfect | Perfect | Major | minor |
| Dorian II | perfect | Major | minor | perfect | Perfect | Major | minor |
| Aeolian VI | perfect | Major | minor | perfect | Perfect | minor | minor |
| Phrygian III | perfect | minor | minor | perfect | Perfect | minor | minor |
| Locrian VII | perfect | minor | minor | perfect | diminished | minor | minor |
The first three modes are termed major, the remaining four are minor. A mode is deemed major or minor by the intervallic relationship between the 1st and 3rd scale degrees. A mode is considered minor if the 1st and 3rd scale degrees form a minor 3rd (3 semitones above the root). A major mode instead has a major 3rd (4 semitones) from the 1st scale degree to the 3rd.
The Locrian mode is traditionally considered theoretical rather than practical because the interval between the 1st and 5th scale degrees is diminished rather than perfect, which creates difficulties in voice leading. However, Locrian is recognized in jazz theory as the preferred mode to play over a iiø7 chord in a minor iiø7-V7-i progression, where it is called a 'half-diminished' scale.
Major modes The Ionian mode is identical to a major scale. The Lydian mode is a major scale with a raised 4th scale degree. The Mixolydian mode is a major scale with a lowered 7th scale degree.
Minor modes The Aeolian mode is identical to a natural minor scale. The Dorian mode is a natural minor scale with a raised 6th scale degree. The Phrygian mode is a natural minor mode with a lowered 2nd scale degree.
Diminished modes Locrian is the only mode with a lowered 5th or diminished 5th. This interval is the same distance (6 semitones from the first) as an augmented 4th which one would find in the lydian mode. Locrian's (I)'s seventh chord is naturally a half diminished seventh which is a diminished triad with a minor seventh on top. In Classical music, the Locrian exists only in theory, but certain Jazz musicians came at it 'through the back door,' as it were, and, not knowing that it was "supposed to be" only theoretical, used it.
The relationship between the seven modern modes is discussed in more detail in the article on properties of musical modes.
The use and conception of modes or modality today is different from their use and conception in early music. As Jim Samson (1977, p.148) explains, "Clearly any comparison of medieval and modern modality would recognize that the latter takes place against a background of some three centuries of harmonic tonality, permitting, and in the nineteenth century requiring, a dialogue between modal and diatonic procedure."
The Ionian mode is another name for the major mode, in which much Western music is composed. The Aeolian forms the base of the most common Western minor scale; however, a true Aeolian mode composition will use only the seven notes of the Aeolian scale, while nearly every minor mode composition of the common practice period will have some accidentals on the sixth and seventh scale degrees in order to facilitate the cadences of western music.
Besides the Ionian major and modern (harmonic/melodic) minor modes, the other modes have limited use in music today. Folk music is often best analysed in terms of modes. For example, in Irish traditional music the Ionian, Dorian, Aeolian and Mixolydian modes occur (in roughly decreasing order of frequency); the Phrygian mode is an important part of the flamenco sound. The Dorian mode is also found in other folk music, particularly Latin and Laotian music, while Phrygian is found in some Central European or stylized Arab music, whether as natural Phrygian or harmonic Phrygian (Phrygian Dominant), which has a raised third (the so-called "gypsy scale"). Mixolydian mode is quite common in jazz and most other forms of popular music. Because of its dream-like sound, the Lydian mode is most often heard in soundtrack and video game music.
Some works by Beethoven contain modal inflections, and Chopin, Berlioz, and Liszt made extensive use of modes. They influenced nineteenth century Russian composers, including Mussorgsky and Borodin; many twentieth century composers drew on this earlier work in their incorporation of modal elements, including Claude Debussy, Leoš Janáček, Jean Sibelius, Ralph Vaughan Williams and others. Zoltán Kodály, Gustav Holst, Manuel de Falla use modal elements as modifications of a diatonic background, while in the music of Debussy and Béla Bartók modality replaces diatonic tonality. (Samson 1977)
They have also been used in popular music, especially in rock music. Some notable examples of songs using modality include Scarborough Fair, which uses the Dorian mode, and many of the jam-songs of The Grateful Dead. The Dorian and Aeolian modes are also very prevalent in modern punk and post-hardcore music.
While remaining relatively uncommon in modern (Western) popular music, the darker tones implied by the flatted 2nd and/or 5th degrees of (respectively) the Phrygian and Locrian modes are evident in diatonic chord progressions and melodies of many guitar-oriented rock bands, especially in the late 1980s and early 1990s, as evidenced on albums such as Metallica's "Ride the Lightning" and "Master of Puppets", among others.
| Mode | Ionian | Dorian | Phrygian | Lydian | Mixolydian | Aeolian | Locrian |
|---|---|---|---|---|---|---|---|
| Chord | Cmaj7 | Dm7 | Esus9 (or Em7) | Fmaj711 | G7 | Am7 | Bø (Bm75) |
Although both Dorian and Aeolian can be played over a minor seventh (m7) chord, the Dorian mode is most commonly used in straightahead jazz because the Dorian mode has a whole step between the 5th and 6th scale degrees, in contrast to the more jarring half step in the Aeolian. Also note that the most common jazz cadence or chord progression is a ii-V-I which suggests Dorian mode in the case of the ii chord.
Similarly, over a half-diminished (ø or m7♭5) chord, many jazz musicians will alter the Locrian mode by raising the second degree of the scale by a semitone, in order to form a major ninth over the chord (e.g. C over Bø), rather than the more dissonant minor ninth (e.g. C natural over Bø). This scale is also called the 6th mode of the melodic minor. And over the "sus9" chord, the sixth scale degree of the Phrygian mode is often raised by a semitone, in order to make a major sixth in the chord, rather than the more dissonant minor sixth. This mode is also called the 2nd mode of melodic minor. See Other modes below for more about the melodic minor modes and their associated chords.
| Mode | I | II | III | IV | V | VI | VII |
|---|---|---|---|---|---|---|---|
| Name | Melodic Minor | Dorian 2 | Lydian augmented | Lydian dominant | Mixolydian 6 or "Hindu" | half-diminished (or) Locrian Natural 2nd | altered (or) diminished whole-tone (or) Super Locrian |
| Chord | C-maj7 | D-9 | Emaj5 | F711 | G713 | Aø (or) A-75 | B7alt |
| Mode | I | II | III | IV | V | VI | VII |
|---|---|---|---|---|---|---|---|
| Name | Harmonic Minor | Locrian Natural 6th | Harmonic Major 5 | Dorian 4 | Phrygian major 3rd | Lydian 2 | Super locrian diminished |
| Chord | C-minmaj7 | Dø | E-maj75 | F-7 | G7 | A-maj7 (or) A-minmaj7 | B-Dim7 |
Most of these chords and modes are commonly used in jazz; the min/maj chord, 711 and alt were in common use in the bebop era (indeed, the Lydian dominant scale and 711 chord practically defined the bebop sound), while Coltrane-era and later jazz made extensive use of sus9 chords. Maj5 is less common, but appears in Wayne Shorter's compositions. The 67 is rarely seen as such.
Though the term "mode" is still used in this case (and is useful in recognizing that these scales all have a common root, that is the melodic minor scale); it is more common for musicians to understand the term "mode" to refer to Ionian, Dorian, Phrygian, Lydian, Mixolydian, Aeolian, or Locrian scales. In everyday speech, this is the most common understanding. But in truth, any scale can be *used* as a mode by establishing its final as the tonal center and emphasizing its characteristic color pitches.
However, strictly speaking, for any possible scale, the number of possible distinct melodic modes is dictated by the pattern of intervals in the scale. For scales built of a pattern of intervals that only repeats at the octave, the number of modes is the number of notes in the scale: such 6-note scales have 6 modes, 5-note scales have 5 modes, etc. Scales that repeat their interval pattern at some subdivision of the octave, however, have only as many modes as notes within that subdivision: e.g. the diminished scale, which is built of alternating whole and half steps, has only two distinct modes, since all odd-numbered modes are equivalent to the first (starting on the whole step) and all even-numbered modes are equivalent to the second (starting on the half step). These scales are sometimes referred to as modes of limited transposition. The chromatic and whole-tone scales, each containing only steps of uniform size, have only a single mode each, as any rotation of the sequence results in the same sequence.
While most scales (a defined number of notes occurring in defined intervals) have commonly accepted names, most of the modal variations of the more obscure scales do not, and are instead referred to as "3rd mode of [your-scale-name-here]", etc.
The Greek modes were:
Plato felt that playing music in a particular mode would incline one towards specific behavior associated with that mode, and suggested that soldiers should listen to music in Dorian or Phrygian modes to help make them stronger, but avoid music in Lydian, Mixolydian or Ionian modes, for fear of being softened. Plato believed that a change in the musical modes of the state would cause a wide-scale social revolution.
The philosophical writings of Plato and Aristotle (c. 350 BC) include sections that describe the effect of different musical modes on mood and character formation. For example, this quote from Aristotle's Politics:
Plato and Aristotle describe the modes to which a person listened as molding the person's character. The modes even made the person more or less fit for certain jobs. The effect of modes on character and mood was called the "ethos of music".
The eight church modes, or Gregorian modes, can be divided into four pairs, where each pair shares the "final" note and the four notes above the final. If the "scale" is completed by adding three higher notes, the mode is termed authentic, while if the scale is completed by adding three lower notes, the mode is called plagal (serious). Otherwise explained: if the melody moves mostly above the final, with an occasional cadence to the sub-final, the mode is authentic. Plagal modes shift range and also explore the fourth below the final as well as the fifth above.
The pairs are organized so that the modes sharing a final note are numbered together, with the odd numbers used for the authentic modes and the even numbers for the plagal modes.
In addition, each mode has a "dominant" or "reciting tone", which is the tenor of the psalm tone. The reciting tones of all authentic modes began a fifth above the final, with those of the plagal modes a third above. However, the reciting tones of modes 3, 4, and 8 rose one step during the tenth and eleventh centuries with 3 and 8 moving from b to c' (half step) and that of 4 moving from g to a (whole step) (Hoppin 1978, p.67).
Only one accidental is used commonly in Gregorian chant—si (B) may be lowered by a half-step. This usually (but not always) occurs in modes V and VI, and is optional in other modes.
| Mode | I | II | III | IV | V | VI | VII | VIII |
|---|---|---|---|---|---|---|---|---|
| Name | Dorian | Hypodorian | Phrygian | Hypophrygian | Lydian | Hypolydian | Mixolydian | Hypomixolydian |
| Final (note) | D | D | E | E | F | F | G | G |
| Final (solfege) | re | re | mi | mi | fa | fa | sol | sol |
| Dominant (note) | A | F | B-C | A | C | A | D | C |
| Dominant (solfege) | la | fa | si-do | la | do | la | re | do |
Given the confusion between ancient, Early, and modern terminology, "today it is more consistent and practical to use the traditional designation of the modes with numbers one to eight," (Curtis 1998) using Roman numeral (I-VIII), rather than using the pseudo-Greek naming system. Contemporary terms, also used by scholars, are simply Latin denominators: Protus, Deuterus, Tritus and Tetrardus, in practice used as : protus authentus / plagalis.
Carl Dahlhaus (1990, p.192) lists "three factors that form the respective starting points for the modal theories of Aurelian of Réôme, Hermannus Contractus, and Guido of Arezzo:
The oldest medieval treatise regarding modes is Musica disciplina by Aurelian of Réôme while Hermannus Contractus was the first to define modes as partitionings of the octave (ibid, p.192-191).
Various interpretations of the "character" imparted by the different modes have been suggested. Three such interpretations, from Guido of Arezzo (995-1050), Adam of Fulda (1445-1505), and Juan de Espinoza Medrano (1632-1688), follow:
| Name | Mode | D'Arezzo | Fulda | Espinoza | Example chant |
|---|---|---|---|---|---|
| Dorian | I | serious | any feeling | happy, taming the passions | Veni sancte spiritus |
| Hypodorian | II | sad | sad | serious and tearful | Iesu dulcis amor meus |
| Phrygian | III | mystic | vehement | inciting anger | Kyrie, fons bonitatis |
| Hypophrygian | IV | harmonious | tender | inciting delights, tempering fierceness | Conditor alme siderum |
| Lydian | V | happy | happy | happy | Salve Regina |
| Hypolydian | VI | devout | pious | tearful and pious | Ubi caritas |
| Mixolydian | VII | angelical | of youth | uniting pleasure and sadness | Introibo |
| Hypomixolydian | VIII | perfect | of knowledge | very happy | Ad cenam agni providi |
Most of the theoretical writings on Gregorian chant modes postdate the composition of the early Gregorian chant repertoire, which was not composed with the intention of conforming to particular modes. As a result, for these chants, the application of a mode number can be only approximate. Later chants, however, were written with a conscious eye on the eight modes.