Unit Big Picture
This unit transitions from the study of individual notes and intervals to the construction of chords, the fundamental building blocks of harmony. You will learn to build, identify, and label three-note triads and four-note seventh chords. By introducing Roman numerals and figured bass, this unit provides the essential symbolic language for analyzing how chords function within a key and connect to one another, laying the foundation for understanding harmonic progression.
Core Threads
Thread 1: Functional Harmony & Cadences
Roman numerals are introduced to label diatonic chords (chords built from a scale) and assign them a harmonic function (Tonic, Predominant, Dominant) based on their scale degree root.
Chord inversions alter the stability of a chord by placing a note other than the root in the bass, which affects its harmonic weight and role within a phrase.
Thread 2: Voice-Leading & Texture
Figured bass is a notational shorthand that uses numbers below a bass line to indicate the intervals (and thus, the specific notes) to be played above it, controlling the vertical structure.
Using inversions allows for smoother, more melodic bass lines by avoiding the large leaps between chord roots that often occur in root-position-only progressions.
Concept Progression
| Step | Concept | Builds On | Why It Matters |
|---|---|---|---|
| 1 | Triad Qualities | Major/minor/perfect intervals | Establishes the four basic chord sounds (M, m, d, A). |
| 2 | Diatonic Chords & Roman Numerals | Major/minor scales, triad qualities | Systematizes harmony within a key, assigning function to chords. |
| 3 | Chord Inversions & Figured Bass | Triad construction | Introduces harmonic variety and control over the bass line's contour. |
| 4 | Seventh Chords & Inversions | Triads and figured bass | Adds a fourth note, creating richer, more dissonant harmonies. |
Turning Points
| New Tool Introduced | What It Enables | Why It Mattered |
|---|---|---|
| Roman Numerals | Labeling chords by their scale-degree root and quality. | Shifts focus from isolated chords to chords with functional roles. |
| Figured Bass | Precisely indicating chord inversions and notes above a bass line. | Provides a system for controlling harmony and voice-leading. |
| The Seventh Chord | Creating stronger harmonic tension, especially the dominant 7th (V7). | Becomes the engine of tonal harmony, driving music toward resolution. |
Unit Evidence Bank
Triad: A three-note chord built of stacked thirds. The four basic qualities are major, minor, diminished, and augmented.
Seventh Chord: A four-note chord built of stacked thirds, created by adding another third above a triad.
Chord Quality: The sound of a chord, determined by the specific combination of major and minor thirds used to build it.
Root: The fundamental note upon which a chord is built in its simplest, root position form.
Inversion: The arrangement of a chord where a note other than the root is in the lowest-sounding voice (the bass).
Roman Numeral: A symbol (e.g., I, ii, V) that identifies a chord's root by scale degree and its quality by case (upper/lowercase).
Figured Bass: Numbers written below a bass note to indicate the intervals required to form the chords above it.
Diatonic: Notes or chords that belong naturally to the key signature of a given passage.
Topic Navigator
| Topic Title | What This Adds (≤10 words) |
|---|---|
| 3.1: Triad and Chord Qualities | Building blocks: constructing the four basic triad types. |
| 3.2: Diatonic Chords and Roman Numerals | Context: assigning function to triads within a key. |
| 3.3: Chord Inversions and Figures | Voicing: rearranging triads and labeling them with figures. |
| 3.4: Seventh Chords | Expansion: adding a fourth note for more complexity. |
| 3.5: Seventh Chord Inversions and Figures | Voicing II: rearranging seventh chords and labeling their inversions. |
| 3.6: Causation in Music Fundamentals | Synthesis: connecting chord choice to musical effect and function. |
Exam Skills Focus
Functional: A chord's Roman numeral determines its function, which predicts its likely destination (e.g., V leads to I).
Voice-Leading: Figured bass numbers dictate specific intervals above the bass, constraining melodic options for upper voices.
Aural: The distinct sound of a triad's quality (major/minor/etc.) is the primary cue for aural identification.
Common Misconceptions & Clarifications
Misconception: The bass note is always the root of the chord.
- Clarification: The bass note is only the root in root position. In inversions, the third, fifth, or seventh is in the bass.
Misconception: Figured bass numbers represent scale degrees.
- Clarification: Figures represent the generic intervals (e.g., 6, 4) above the specific bass note, not scale degrees.
Misconception: The Roman numeral V always represents a major chord.
- Clarification: In natural minor, the v chord is minor. The leading tone is typically raised to create a major V chord for a stronger pull to tonic.
Summary
This unit establishes the core components of Western harmony. By learning to build, identify, and invert triads and seventh chords, you gain the tools to understand vertical sonorities. The introduction of Roman numerals provides a system for analyzing a chord's function within a key, while figured bass offers a method for precisely controlling voice-leading. These skills are not isolated; they work together, allowing you to move from simply naming chords to understanding why they are chosen and how they create coherent musical phrases.