Modes

A mode is what you get when you keep the seven notes of a major scale but make a different note the home. The notes do not change; the centre of gravity does, and that is enough to change the whole mood.

Play the white keys from C to C and you hear C major. Now play the same white keys from D to D. Nothing was added or removed, yet the scale sounds darker and more serious. That scale is D Dorian.

Why does it sound different? Because your ear measures every note from home, as an interval. Measured from D, the third note is F: a minor third above home. Measured from C, the third note was E: a major third. Same keys, new intervals.

There are two equally true ways to describe any mode, and you need both. The relative view says *which major scale the notes come from*; the parallel view says *how the mode differs from major on the same home note*.

The parallel view is where the degree formula comes from. D major is 1 2 3 4 5 6 7 = D E F# G A B C#. D Dorian is D E F G A B C: the F# became F and the C# became C. So Dorian is:

Each degree names an interval above home. b3 is a minor third, b7 a minor seventh. A formula is portable: put 1 2 b3 4 5 6 b7 on C and you get C Dorian: C D Eb F G A Bb. That is the relative rotation of Bb major, but you do not need to know that to play it. The formula already told you every note.

Ionian is the mode built on degree 1 of the major scale, which means Ionian simply *is* the major scale. It is our reference point: every other mode is described as a change to it.

Two features make Ionian sound so settled. Its 3 is a major third, so the home chord 1 3 5 is a bright major triad. And its 7 is a major seventh, the leading tone that sits right under the octave, so the V chord (G B D in C) pulls hard back to I. Most pop, classical and folk melodies live here.

Dorian is the mode built on degree 2 of the major scale. It is a minor mode, because its 3 is a minor third, but its 6 stays a major sixth, and that one bright note gives Dorian its cool, hopeful, slightly jazzy colour.

Compare it with natural minor 1 2 b3 4 5 b6 b7: the only difference is the 6. Dorian's 6 is a major sixth above home; natural minor's b6 is a minor sixth. In D Dorian that note is B; in D natural minor it would be Bb. That major sixth also makes the IV chord major (G B D in D Dorian), which is why the classic Dorian vamp is i-IV: Dm to G.

Phrygian is the mode built on degree 3 of the major scale. It is a minor mode with one unmistakable feature: the 2 is lowered to a minor second, the smallest step there is, so the second note leans right on top of home. That crunch gives Phrygian its dark, Spanish, dramatic sound.

Compare it with natural minor 1 2 b3 4 5 b6 b7: everything matches except the b2. Natural minor's 2 is a major second above home; Phrygian's b2 is a minor second. In E Phrygian, F leaning down onto E is the whole flavour. The chord built on that b2 is major (F A C), so the signature Phrygian vamp is i-bII: Em to F, the sound of flamenco and heavy metal alike.

Lydian is the mode built on degree 4 of the major scale. It is a major mode, with a major third and a leading-tone 7, and it has a single change: the 4 is raised from a perfect fourth to an augmented fourth. That #4 lifts the scale off the ground and gives it a dreamy, floating, film-score quality.

In plain major, degree 4 pulls down onto 3 (F → E in C). Raise it to F# and that pull disappears: the note floats instead. The chord built on degree 2 becomes major (G B D in F Lydian, D F# A in C Lydian), so the signature Lydian vamp is I-II: F to G, two major chords a major second apart.

Mixolydian is the mode built on degree 5 of the major scale. It is a major mode with one change: the 7 is lowered from a major seventh to a minor seventh. Losing the leading tone relaxes the scale. This is the sound of blues, rock and a great deal of folk music.

Because the 7 is a minor seventh, the home chord with a seventh is a dominant seventh 1 3 5 b7 (G B D F = G7) that does *not* need to resolve anywhere. It just sits there sounding bluesy. The chord built on the b7 is major (F A C in G Mixolydian), giving the signature vamp I-bVII: G to F.

Aeolian is the mode built on degree 6 of the major scale, and it is exactly the natural minor scale you met in the Relative Minor chapter. Three degrees are lowered compared with major: the 3, 6 and 7 become a minor third, a minor sixth and a minor seventh.

Aeolian is the middle of the three minor modes: Dorian is Aeolian with a major sixth, Phrygian is Aeolian with a b2. Its b6 and b7 both carry major chords, F A C and G B D in A Aeolian, so its signature vamp is i-bVI-bVII: Am to F to G, one of the most common sounds in pop and rock.

Locrian is the mode built on degree 7 of the major scale, and it is the odd one out: besides a lowered 2, 3, 6 and 7, its 5 is lowered too, from a perfect fifth to a diminished fifth. With no perfect fifth above home, the home chord is diminished, and the scale struggles to feel at rest.

The home triad 1 b3 b5 is B D F = Bdim, and a diminished chord always sounds like it wants to move. That is why whole songs in Locrian are rare. It does appear in metal riffs and in jazz, where the Locrian scale is the natural choice over a m7b5 chord (Bm7b5 = B D F A, the vii chord of C major).

Put all seven modes on the same home note C and line them up from brightest to darkest, and a beautiful pattern appears: each step down flattens exactly one more degree.

Lydian sits at the bright end with its #4. Ionian has no alterations. Then flats arrive one at a time, b7, b3, b6, b2, b5, and the mood darkens with each one. The order of the flats is no accident: B E A D G is the order of flats in key signatures, moving around the circle of fifths.

Every mode has one characteristic note: the single degree that tells it apart from plain major (for the major modes) or from natural minor (for the minor modes). Lean on that note, and on the chord that contains it, and the mode announces itself.

Each vamp works the same way: the home chord says *this is 1*, and the second chord contains the characteristic note. D major over a C home puts the #4 (F#) in your ear; Bb major puts the b7; F major in C Dorian contains the major sixth (A); Db major hammers the b2.

Step back and the seven modes stop being seven things to memorise and become one system. Three are major (Lydian, Ionian, Mixolydian), three are minor (Dorian, Aeolian, Phrygian), and one is diminished (Locrian). Each is a single-degree tweak away from its neighbour.

Here is the bigger idea. Because every mode on C shares the same home note, a piece in C major can borrow a chord from C Mixolydian (Bb), from C Aeolian (Ab, Fm) or from C Lydian (D) without leaving home. That technique is called modal interchange, and it gets its own chapter later in the course.

First, though, we take a different route out of the key: in the next chapter we make any chord feel like a temporary home by giving it its own dominant. These are applied dominants, also called secondary dominants.