AP Exams: Music Theory Unit 4, Chords, Seventh Chords, MM7, Mm7, Dominant, mm7, Half-Diminished, Fully-Diminished

What Is This?

Seventh chords are chords that include the seventh note of the scale. They are crucial in music theory and appear frequently in exams, generating questions on chord identification, construction, and function within a key.

Why It Matters

Seventh chords are tested in music theory exams, such as those by the Royal Conservatory of Music and ABRSM, and in college-level music courses. They typically carry 10-20% of the total marks and test your ability to understand and apply complex harmonic structures.

Core Concepts

1. Chord Construction: Understand how to build seventh chords by stacking thirds.
2. Chord Symbols: Recognize and write chord symbols accurately.
3. Chord Function: Know the role of each seventh chord within a key.
4. Distinctions: Be clear on the differences between MM7, Mm7, mm7, half-diminished, and fully-diminished chords.
5. Inversions: Recognize and write seventh chords in different inversions.

Prerequisites

1. Basic Chord Theory: Knowledge of triads (major, minor, diminished, augmented).
2. Scales: Understanding of major and minor scales.
3. Intervals: Recognition and construction of intervals, especially thirds and sevenths.

The Rule-Book (How It Works)

Primary Rule

Seventh chords are built by stacking thirds: 1-3-5-7.

Sub-Rules and Exceptions

• MM7 (Major-Major Seventh): 1-3-5-7 (e.g., C-E-G-B)
• Mm7 (Dominant Seventh): 1-3-5-?7 (e.g., C-E-G-B?)
• mm7 (Minor-Minor Seventh): 1-?3-5-?7 (e.g., C-E?-G-B?)
• Half-Diminished: 1-?3-?5-?7 (e.g., C-E?-G?-B?)
• Fully-Diminished: 1-?3-?5-dim7 (e.g., C-E?-G?-B)

Visual Pattern

Think of the stacking thirds as a staircase: 1 (root), 3 (third), 5 (fifth), 7 (seventh).

Exam / Job / Audit Weighting

• Frequency: Common
• Difficulty Rating: Intermediate
• Question Type: Identification, construction, function within a key

Difficulty Level

Intermediate

Must-Know Rules, Formulas, Standards, or Principles

1. Chord Construction: Stack thirds to build seventh chords.
2. Chord Symbols: Use standard symbols (MM7, Mm7, mm7, ø7, o7).
3. Chord Function: Understand the role of each seventh chord within a key.

Worked Examples (Step-by-Step)

Easy

Question: Identify the seventh chord built on the fifth degree of the C major scale. Step 1: Identify the fifth degree of C major: G. Step 2: Build the chord: G-B-D-F. Answer: G7 (G-B-D-F). Rule Applied: Dominant seventh chord (Mm7).

Medium

Question: Write the mm7 chord built on the second degree of the A minor scale. Step 1: Identify the second degree of A minor: B. Step 2: Build the chord: B-D-F-A. Answer: Bm7 (B-D-F-A). Rule Applied: Minor-minor seventh chord (mm7).

Hard

Question: Identify the half-diminished chord built on the seventh degree of the B? major scale. Step 1: Identify the seventh degree of B? major: A. Step 2: Build the chord: A-C-E?-G. Answer: Aø7 (A-C-E?-G). Rule Applied: Half-diminished seventh chord.

Common Exam Traps & Mistakes

1. Mistake: Confusing Mm7 with mm7.
2. Wrong Answer: Cm7 for C7.

3. Correct Approach: Remember Mm7 has a major triad with a minor seventh.

4. Mistake: Forgetting the diminished seventh in fully-diminished chords.

5. Wrong Answer: C-E?-G?-B? for C-E?-G?-B.

6. Correct Approach: Remember the diminished seventh interval.

7. Mistake: Incorrectly identifying the seventh degree in minor keys.

8. Wrong Answer: G# for G in A minor.
9. Correct Approach: Use the natural minor scale.

Shortcut Strategies & Exam Hacks

• Memory Aid: Use the mnemonic "MM7, Mm7, mm7, ø7, o7" to remember the chord types.
• Elimination Strategy: Eliminate options that don't fit the key or chord function.
• Pattern Recognition: Recognize the interval patterns for quick identification.

Question-Type Taxonomy

1. Identification: "Identify the seventh chord built on the X degree of the Y scale."
2. Mini-Example: "Identify the seventh chord built on the fifth degree of the C major scale."

3. Exams: ABRSM, Royal Conservatory

4. Construction: "Write the X seventh chord built on the Y degree of the Z scale."

5. Mini-Example: "Write the mm7 chord built on the second degree of the A minor scale."

6. Exams: College-level music theory

7. Function: "What is the function of the X seventh chord in the Y key?"

8. Mini-Example: "What is the function of the G7 chord in the key of C major?"
9. Exams: ABRSM, Royal Conservatory

Practice Set (MCQs)

Question 1

Question: Identify the seventh chord built on the third degree of the D major scale. Options: A) Dm7 B) F#m7 C) F#M7 D) F#ø7 Correct Answer: B) F#m7 Explanation: The third degree of D major is F#. The chord is F#-A#-C#-E (mm7). Why the Distractors Are Tempting: A) Confuses the root, C) Incorrect chord type, D) Incorrect chord type.

Question 2

Question: Write the Mm7 chord built on the fifth degree of the G major scale. Options: A) D7 B) Dm7 C) Dø7 D) Do7 Correct Answer: A) D7 Explanation: The fifth degree of G major is D. The chord is D-F#-A-C (Mm7). Why the Distractors Are Tempting: B) Incorrect chord type, C) Incorrect chord type, D) Incorrect chord type.

Question 3

Question: Identify the half-diminished chord built on the seventh degree of the E? major scale. Options: A) Dø7 B) Dm7 C) D7 D) Do7 Correct Answer: A) Dø7 Explanation: The seventh degree of E? major is D. The chord is D-F-A?-C? (half-diminished). Why the Distractors Are Tempting: B) Incorrect chord type, C) Incorrect chord type, D) Incorrect chord type.

Question 4

Question: What is the function of the B7 chord in the key of E major? Options: A) Tonic B) Subdominant C) Dominant D) Mediant Correct Answer: C) Dominant Explanation: B7 is the dominant seventh chord in the key of E major. Why the Distractors Are Tempting: A) Incorrect function, B) Incorrect function, D) Incorrect function.

Question 5

Question: Write the fully-diminished chord built on the seventh degree of the C minor scale. Options: A) Bø7 B) Bo7 C) Bm7 D) B7 Correct Answer: B) Bo7 Explanation: The seventh degree of C minor is B. The chord is B-D-F-A? (fully-diminished). Why the Distractors Are Tempting: A) Incorrect chord type, C) Incorrect chord type, D) Incorrect chord type.

30-Second Cheat Sheet

• MM7: 1-3-5-7
• Mm7: 1-3-5-?7
• mm7: 1-?3-5-?7
• Half-Diminished: 1-?3-?5-?7
• Fully-Diminished: 1-?3-?5-dim7
• Stack Thirds: 1-3-5-7 pattern
• Chord Symbols: MM7, Mm7, mm7, ø7, o7

Learning Path

1. Beginner Foundation: Review basic chord theory and intervals.
2. Core Rules: Learn the construction and symbols of seventh chords.
3. Practice: Identify and write seventh chords in different keys.
4. Timed Drills: Practice under exam conditions.
5. Mock Tests: Take full-length practice exams.

Related Topics

1. Triads: Basic chord theory that seventh chords build upon.
2. Scale Degrees: Understanding the function of chords within a key.
3. Chord Progressions: How seventh chords fit into harmonic progressions.