Modes of the Major Scale

Why This Matters

Understanding modes isn't just about memorizing seven different scales—it's about recognizing how shifting the tonal center within the same pitch collection creates dramatically different musical characters. On the AP Music Theory exam, you're being tested on your ability to identify modes aurally, analyze their interval structures, and understand why each mode produces its distinctive quality. This connects directly to Unit 8's focus on how tonal qualities affect musical character and builds on your foundational understanding of scales from Units 1 and 2.

The key insight is that modes differ by just one or two altered scale degrees compared to major or natural minor, yet these small changes create entirely different emotional landscapes. Whether it's the raised fourth that gives Lydian its floating quality or the lowered second that makes Phrygian sound exotic, each alteration has a specific sonic consequence. Don't just memorize the interval patterns—know which scale degree is altered and what character that alteration creates.

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Modes with Major Quality

These modes share the defining characteristic of a major third above the tonic, giving them a generally bright or stable foundation. The presence of a major third (scale degree 3) establishes the "major" family sound, but each mode's unique alteration creates distinct flavors within that brightness.

Ionian (Major Scale)

• Identical to the major scale—this is your reference point for understanding all other modes
• No altered degrees (1, 2, 3, 4, 5, 6, 7)—the "default" sound of Western tonal music
• Interval pattern: W-W-H-W-W-W-H—memorize this as your baseline for comparing other modes

Lydian

• Raised fourth degree ($\sharp 4$)—the only alteration from Ionian, creating a dreamy, floating quality
• Scale degrees: 1, 2, 3, $\sharp 4$, 5, 6, 7—that tritone between 1 and $\sharp 4$ adds brightness without instability
• Interval pattern: W-W-W-H-W-W-H—three consecutive whole steps at the beginning distinguish it aurally

Mixolydian

• Lowered seventh degree ($\flat 7$)—creates a dominant-seventh sound built into the scale
• Scale degrees: 1, 2, 3, 4, 5, 6, $\flat 7$—the major third keeps it bright while $\flat 7$ adds a bluesy edge
• Interval pattern: W-W-H-W-W-H-W—commonly heard in blues, rock, and folk idioms

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Modes with Minor Quality

These modes share a minor third above the tonic, placing them in the "minor family." The lowered third ($\flat 3$) establishes the darker foundation, but variations in degrees 2, 6, and 7 create distinctly different minor flavors.

Dorian

• Raised sixth degree ($\natural 6$) compared to natural minor—this single bright note within a minor context is Dorian's signature
• Scale degrees: 1, 2, $\flat 3$, 4, 5, 6, $\flat 7$—the natural 6 softens the darkness, making it versatile for jazz and modal music
• Interval pattern: W-H-W-W-W-H-W—listen for that unexpectedly bright sixth in a minor context

Phrygian

• Lowered second degree ($\flat 2$)—creates immediate tension and an exotic, Spanish/flamenco character
• Scale degrees: 1, $\flat 2$, $\flat 3$, 4, 5, $\flat 6$, $\flat 7$—the half step between 1 and $\flat 2$ is its most distinctive feature
• Interval pattern: H-W-W-W-H-W-W—that opening half step is your aural identification key

Aeolian (Natural Minor)

• Equivalent to the natural minor scale—your reference point for comparing minor-quality modes
• Scale degrees: 1, 2, $\flat 3$, 4, 5, $\flat 6$, $\flat 7$—no alterations from natural minor, making it the "default" minor sound
• Interval pattern: W-H-W-W-H-W-W—the relative minor of any major key shares this pattern

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The Unstable Mode: Locrian

This mode stands apart because it lacks a perfect fifth above the tonic, making it inherently unstable. The diminished fifth ($\flat 5$) prevents the tonic triad from being major or minor—it's diminished, which undermines any sense of rest or resolution.

Locrian

• Lowered fifth degree ($\flat 5$)—creates a diminished tonic triad, the most unstable possible foundation
• Scale degrees: 1, $\flat 2$, $\flat 3$, 4, $\flat 5$, $\flat 6$, $\flat 7$—the most alterations from major, the darkest and most dissonant mode
• Interval pattern: H-W-W-H-W-W-W—rarely used as a primary mode due to its lack of tonal stability

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Quick Reference Table

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Self-Check Questions

1. Which two modes share all scale degrees except for degree 6, and how does this single difference affect their character?

2. A melody uses the pitches of C major but consistently emphasizes G as the tonal center and features an F natural prominently. Which mode is this, and what quality does it have?

3. Compare and contrast Lydian and Phrygian: What quality does each have (major/minor), which single degree is altered from its "parent" scale, and what character does each alteration create?

4. Why is Locrian considered the most unstable mode? Identify the specific scale degree that causes this instability and explain its harmonic consequence.

5. If you hear a mode that sounds minor but with an unexpectedly bright quality in the upper tetrachord, which mode is it most likely, and which scale degree creates that brightness?