Scales & Keys
Diatonic Scales
In music theory, a diatonic scale is any heptatonic (seven note) scale that includes five whole steps (whole tones) and two half steps (semitones) in each octave, in which the two half steps are separated from each other by either two or three whole steps, depending on their position in the scale. This pattern ensures that, in a diatonic scale spanning more than one octave, all the half steps are maximally separated from each other (i.e. separated by at least two whole steps). A heptatonic scale is a musical scale that has seven pitches, or tones, per octave. So essentially a diatonic scale is a specific subset of a heptatonic scale.
Ionian (Major) Scale
The Ionian Scale, more commonly known as the major scale is one of the most commonly used musical scales, especially in Western music. Like many musical scales, it is made up of seven notes: the eighth duplicates the first at double its frequency so that it is called a higher octave of the same note (from Latin "octavus", the eighth).
Solfège
In music, solfège or solfeggio in Italian also called sol-fa, solfa, solfeo, among many names, is a mnemonic used in teaching aural skills, pitch and sight-reading of Western music. Solfège is a form of solmization, though the two terms are sometimes used interchangeably. Many might be familiar with the solfège from the Do Re Me song many learned as children.
The Degrees
In music theory, the scale degree is the position of a particular note on a scale relative to the tonic, the first and main note of the scale from which each octave is assumed to begin. Each scale degree has a number and a Latin name. The number is given to each step of the scale, usually starting with 1 for tonic. The Latin names indicate their particular function within the scale. This implies a functional scale, as is the case in tonal music.
Although in this case we are referring to the major scale, the names are the same for the minor scales, only the seventh degree changes name when flattened.
The Latin Term Hierarchy
The following illustration indicates how the Latin terms are applied.
Tonic
In music, the tonic is the first scale degree of the diatonic scale and the tonal center or final
resolution tone that is commonly used in the final cadence in tonal 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.
Two parallel keys have the same tonic. For example, in both C major and C minor, the tonic is C.
However, relative keys (two different scales that share a key signature) have different tonics.
For example, C major and A minor share a key signature that feature no sharps or flats, despite
having different tonic pitches (C and A, respectively).
Supertonic
In music, the supertonic is the second degree of a diatonic scale, one whole step above the tonic.
In the movable do solfège system, the supertonic note is sung as re. The triad built on the supertonic
note is called the supertonic chord. In Roman numeral analysis, the supertonic chord is typically
symbolized by the Roman numeral ii in a major key, indicating that the chord is a minor
chord. In a minor key, it is indicated by ii° if it is built on the a natural minor scale,
indicating that the chord is a diminished chord.
These chords may also appear as seventh chords: in major, as ii7, while in minor as
iiØ7. They are the second-most-common form of nondominant seventh chords.
The supertonic chord normally functions as a predominant chord, a chord that naturally
resolves to chord with dominant function. The supertonic chord lies a fifth above the V chord.
Descending fifths are a strong basis for harmonic motion (see Circle of Fifths).
The supertonic is one of the strongest predominants and approaches the V chord from above by
descending fifth.
Mediant
The mediant, Latin: "being in the middle" is the third scale degree of a diatonic scale,
being the note halfway between the tonic and the dominant. In the movable do solfège system,
the mediant note is sung as mi. While the fifth scale degree is almost always a perfect fifth,
the mediant can be a major or minor third.
The mediant is one of the notes in the tonic triad chord. The mediant is also a note in the submediant
chord.
In Roman numeral analysis, the mediant chord can take several forms. In major scales, the mediant chord
is a minor triad and is symbolized with the Roman numeral iii.
In natural minor scales, the mediant is a major triad and is symbolized with the Roman numeral III.
In harmonic minor scales and ascending melodic minor scales, the seventh scale degree is raised by a
half step from the subtonic b7 to the leading tone natural 7,
creating an augmented triad that is symbolized with the Roman numeral
bIII+ (flat III augmented).
Subdominant
The subdominant is the fourth tonal degree of the diatonic scale. It is so called because it is the
same distance below the tonic as the dominant is above the tonic, in other words, the tonic is the
dominant of the subdominant. It also happens to be the note one step below the dominant. In the
movable do solfège system, the subdominant note is sung as fa.
The triad built on the subdominant note is called the subdominant chord. In Roman numeral analysis,
the subdominant chord is typically symbolized by the Roman numeral "IV"
in a major key, indicating that the chord is a major triad. In a minor key, it is symbolized by
"iv", indicating that the chord is a minor triad.
These chords may also appear as seventh chords: in major, as IVM7,
or in minor as iv7 or sometimes IV7.
A cadential subdominant chord followed by a tonic chord produces the so-called plagal cadence.
Dominant
In music, the dominant is the fifth scale degree of the diatonic scale. It is called the dominant
because it is second in importance to the first scale degree, the tonic. In the movable do solfège
system, the dominant note is sung as "Sol".
The triad built on the dominant note is called the dominant chord. This chord is said to have
dominant function, which means that it creates an instability that requires the tonic for resolution.
Dominant triads, seventh chords, and ninth chords typically have dominant function. Leading-tone triads
and leading-tone seventh chords may also have dominant function.
In music theory, the dominant triad is a major chord, symbolized by the Roman numeral "V"
in the major scale. In the natural minor scale, the triad is a minor chord, denoted by "v".
However, in a minor key, the seventh scale degree is often raised by a half step creating a major chord.
These chords may also appear as seventh chords: typically as a dominant seventh chord, V7,
but occasionally in minor as a minor seventh chord v7 with passing function.
The dominant key is the key whose tonic is a perfect fifth above (or a perfect fourth below) the tonic of the
main key of the piece. Put another way, it is the key whose tonic is the dominant scale degree in the main key.
If, for example, a piece is written in the key of C major, then the tonic key is C major and the dominant key is
G major since G is the dominant note in C major.
Music which modulates (changes key) often modulates to the dominant key. Modulation to the dominant often creates
a sense of increased tension; as opposed to modulation to the subdominant (fourth note of the scale),
which creates a sense of musical relaxation.
Submediant
The submediant is the sixth degree of a diatonic scale. The submediant ("lower mediant") is named thus
because it is halfway between the tonic and the subdominant ("lower dominant") or because its position below
the tonic is symmetrical to that of the mediant above.
In the movable do solfège system, the submediant is sung as la in a major mode and fa in a minor mode.
It is occasionally called superdominant, as the degree above the dominant. This is its normal name (sus-dominante) in
French.
In Roman numeral analysis, the triad formed on the submediant is typically symbolized by "VI"
if it is a major triad (the default in a minor mode) and by "vi" if it is a minor triad
(the default in a major mode).
Amongst the primary roles played by the submediant chord is that in the deceptive cadence, V7 - vi
in major or V7 - VI in minor.
Subtonic
The subtonic is the degree of a musical scale which is a whole step below the tonic note. In a major key, it is a lowered,
or flattened, seventh scale degree. It appears as the seventh scale degree in the natural minor and descending melodic
minor scales but not in the major scale. In major keys, the subtonic sometimes appears in borrowed chords.
In the movable do solfège system, the subtonic note is sung as te (or ta).
The subtonic can be contrasted with the leading note, which is a half step below the tonic. The distinction between
leading note and subtonic has been made by theorists since at least the second quarter of the 20th century.
Before that, the term subtonic often referred to the leading tone triad, for example.
The triad built on the subtonic note is called the subtonic chord. In Roman numeral analysis, the subtonic chord
is symbolized by the Roman numeral bVII in a major key.
In a minor key, it is often written as VII, the flat symbol being often
omitted by some theorists because the subtonic note appears in the natural minor scale. The flat symbol is
used for the major scale because the subtonic is a non-diatonic note.
Leading Tone
In music theory, a leading-tone (also called a subsemitone, and a leading-note in the UK) is a note or pitch
which resolves or "leads" to a note one semitone higher or lower, being a lower and upper leading-tone,
respectively. Typically, the leading tone refers to the seventh scale degree of a major scale,
a major seventh above the tonic. In the movable do solfège system, the leading-tone is sung as ti.
A leading-tone triad, which is a diminished triad, is a triad built on the seventh scale degree in a major key,
while a leading-tone seventh chord is a seventh chord built on the seventh scale degree. The seventh chord
built on the leadiing tone is what is often called a half-diminished seventh or a minor seventh with a
flattened fifth.
A leading-tone chord is a triad built on the seventh scale degree in major and the raised seventh-scale-degree
in minor. The quality of the leading-tone triad is diminished in both major and minor keys.
The leading-tone triad is used in several functions. It is commonly used as a passing chord between a root
position tonic triad and a first inversion tonic triad that is,
"In addition to its basic function of passing between I and I6,
VII6 has another important function, it can form a neighboring chord to
I or I6. In that instance, the leading-tone
triad prolongs tonic through neighbor and passing motion.
Ionian (Major) Scale
Aeolian (Natural Minor) Scale
For each major scale, there is a corresponding natural minor scale, sometimes called its relative minor. It uses the same sequence of notes as the corresponding major scale but starts from a different note. That is, it begins on the sixth degree of the major scale and proceeds step-by-step to the first octave of the sixth degree. A sequence of successive natural notes starting from A is an example of a natural minor scale, called the A natural minor scale.
The following scale of C Minor, is the relative minor to E Flat Major.
Harmonic Minor Scale
The Harmonic Minor Scale and the Melodic Minor Scale Ascending, are not technically Diatonic Scales, but are Heptatonic Scales. This is because they don't follow the rules for a diatonic scale.
Melodic Minor Scale Ascending
Melodic Minor Scale Descending
Modal Diatonic Scales
In its most simplistic interpretation, modal diatonic scales are the scales derived from using a degree, other than the tonic, of a major scale. If you take the key of C major and create a scale based upon the second note, D, instead of the first note, C, that scale is known as D Dorain. If you build a scale starting on the third note, E, that scale is known as E Phrygian. If you build a scale starting on the fourth note, F, that scale is known as F Lydian. If you build a scale starting on the fifth note, G, that scale is known as G Mixolydian. If you build a scale starting on the sixth note, A, that scale is known as A Aeolian (The natural minor). If you build a scale starting on the seventh note, B, that scale is known as B Locrian. Each one of these scales has a different pattern of whole note and half notes.
Dorian Scale
Often associated with medieval music. Modern examples of songs that use Dorian mode are: Evil Ways, Moondance, Billie Jean, Scarborough Fair, Mad World, Riders on the Storm, No Quarter, Norwegian Wood, Wicked Game, and Breathe.
Phrygian Scale
In modern western music (from the 18th century onward), the Phrygian mode is related to the modern natural minor scale, also known as the Aeolian mode, but with the second scale degree lowered by a semitone, making it a minor second above the tonic, rather than a major second. Modern examples of songs that use Dorian mode are: Wherever I May Roam, Things We Said Today, Waiting For The Sun, Gin and Juice, and Baby Got Back.
Lydian Scale
The Lydian scale can be described as a major scale with the fourth scale degree raised a semitone, making it an augmented fourth above the tonic, e.g., an F-major scale with a B rather than Bb. This mode's augmented fourth and the Locrian mode's diminished fifth are the only modes to have a tritone above the tonic. Modern examples of songs that use Dorian mode are: Blue Jay Way, Waltz #1, Man on the Moon, Dreams, Simpson's Theme, and Freewill.
Mixolydian Scale
The modern Mixolydian scale is the fifth mode of the major scale (Ionian mode). That is, it can be constructed by starting on the fifth scale degree (the dominant) of the major scale. Because of this, the Mixolydian mode is sometimes called the dominant scale. Modern examples of songs that use Dorian mode are: Sweet Child of Mine, You Really Got Me, Thunderstruck, I Feel Fine, Shake It Off, Clocks, L.A. Woman, If I Needed Someone, and No Rain.
Locrian Scale
Locrian mode isn't really a practical mode. Historically, it was never used. This mode sounds so odd and unclear; it features little tension and resolution like the other modes do.
Pentatonic Scales
Pentatonic scales contain five notes in contrast to the seven note heptatonic scales in the previous examples.
Major Pentatonic Scale
The major pentatonic scale may be thought of as a gapped or incomplete major scale, using scale tones 1, 2, 3, 5, and 6 of the major scale. One construction takes five consecutive pitches from the circle of fifths; starting on C, these are C, G, D, A, and E. Rearranging the pitches to fit into one octave creates the major pentatonic scale: C, D, E, G, A.
Suspended Pentatonic Scale
Minor Blues Pentatonic Scale
Major Blues Pentatonic Scale
Minor Pentatonic Scale
Although various hemitonic pentatonic scales might be called minor, the term is most commonly applied to the relative minor pentatonic derived from the major pentatonic, using scale tones 1, b3, 4, 5, and b7 of the natural minor scale. (It may also be considered a gapped blues scale.) The C minor pentatonic scale, the relative minor of the E-flat pentatonic scale, is C, E-flat, F, G, B-flat. The A minor pentatonic, the relative minor of C pentatonic, comprises the same tones as the C major pentatonic, starting on A, giving A, C, D, E, G. This minor pentatonic contains all three tones of an A minor triad.
Hexatonic Scales
Hexatonic scales contain six notes. The most popular of these would probably be the so called Blues Scale. The fourth degree of the scale has a flattened fifth note whic is often called the blues note.
Blues Scale
The blues scale is so named for its use of blue notes. Since blue notes are alternate inflections, strictly speaking there can be no one single blues scale, but the scale most commonly called the blues scale comprises the minor pentatonic scale and an additional flat 5th scale degree: C Eb F Gb G Bb C.
Augmented Scale
The augmented scale, also known in jazz theory as the symmetrical augmented scale, is so called because it can be thought of as an interlocking combination of two augmented triads an augmented second or minor third apart: C E G# and Eb G B. It may also be called the "minor-third half-step scale", owing to the series of intervals produced.
Prometheus Scale
The Prometheus scale is so called because of its prominent use in Alexander Scriabin's symphonic poem Prometheus: The Poem of Fire. Scriabin himself called this set of pitches, voiced as the simultaneity (in ascending order) C Gb Bb E A D the "mystic chord". Others have referred to it as the "Promethean chord". It may be thought of as C Lydian dominant without the 5th degree.
Tritone Scale
The tritone scale, C Db E Gb G Bb, is enharmonically equivalent to the Petrushka chord; it means a C major chord (C E G) + Gb major chord's 2nd inversion (Db Gb Bb).
Key Signature
Rather than have a music score be littered with accidental signs, a key signature can be put at the beginning of the measure or at the begining of the bar where the key changes. A key signature indicates which notes should be sharpened or flattened.
C Major or A Minor
Zero sharps or flats
G Major or E Minor
One sharp
D Major or B Minor
Two sharps
A Major or F# Minor
Three sharps
E Major or C# Minor
Four sharps
B Major or G# Minor
Five sharps
F# Major or D# Minor
Six sharps
C# Major or A# Minor
Seven sharps
F Major or D Minor
One flat
Bb Major or G Minor
Two flats
Eb Major or C Minor
Three flats
Ab Major or F Minor
Four flats
Db Major or Bb Minor
Five flats
Gb Major or Eb Minor
Six flats
Cb Major or Ab Minor
Seven flats
