Harmonic analysis is the key to unlocking a song's inner workings. It's like decoding a musical puzzle, revealing how chords work together to create tension, resolution, and emotional impact. Understanding this helps you grasp the bigger picture of chord progressions and cadences.

By breaking down a piece into its harmonic elements, you can see how composers use chords to guide listeners through a musical journey. This knowledge is crucial for writing your own music, as it shows you how to craft compelling progressions and use cadences effectively.

Roman Numeral Analysis

Chord Identification and Qualities

• Roman numerals represent chords based on their scale degree within a key
  • Uppercase numerals (I, IV, V) indicate major chords
  • Lowercase numerals (ii, iii, vi) indicate minor chords
• Chord qualities are determined by the intervals above the root
  • Major chords: major third and perfect fifth (C, E, G)
  • Minor chords: minor third and perfect fifth (A, C, E)
  • Diminished chords: minor third and diminished fifth (B, D, F)

Chord Functions and Progressions

• Primary chord functions in tonal harmony
  • Tonic (I): provides a sense of stability and resolution
  • Subdominant (IV): creates a sense of departure from the tonic
  • Dominant (V): builds tension and leads back to the tonic
• Secondary chords provide additional harmonic color and can serve as substitutes
  • Supertonic (ii), mediant (iii), submediant (vi), leading tone (vii°)
• Non-diatonic chords are identified using Roman numerals with additional symbols
  • Secondary dominants (V/V), borrowed chords (bVI), Neapolitan chords (bII)

Harmonic Structure Analysis

Chord Progressions and Harmonic Motion

• Chord progressions create a sense of harmonic motion and tension-resolution
  • Common progressions: I-IV-V-I, I-vi-IV-V, ii-V-I
  • Each progression has a characteristic sound and function
• Harmonic rhythm: the rate at which chords change
  • Interacts with melodic and rhythmic elements of the composition
• Recurring harmonic patterns, sequences, or motifs contribute to structure and coherence

Cadences and Phrase Endings

• Cadences are specific chord progressions that occur at the ends of phrases or sections
  • Provide a sense of closure or transition
• Perfect authentic cadence (PAC): V-I with the root in the soprano
  • Provides the strongest sense of resolution
• Imperfect authentic cadence (IAC): V-I with a non-root in the soprano
  • Offers a slightly weaker resolution
• Plagal cadence (PC): IV-I
  • Creates a sense of subdominant-to-tonic resolution
• Half cadence (HC): ends on V
  • Creates a sense of incompleteness or anticipation
• Deceptive cadence (DC): V-vi
  • Subverts the expected resolution to the tonic, creating surprise or prolongation of tension

Insights from Harmonic Analysis

Tonal Center, Mode, and Modulations

• Harmonic analysis reveals the tonal center and mode of a piece
  • Identifies modulations to different keys
• Frequency and types of chord progressions indicate style, genre, or historical period
  • Comparing harmonic language illuminates stylistic similarities, differences, and innovations
• Non-diatonic chords highlight moments of harmonic tension, color, or departure from the key
  • Secondary dominants (V/ii), borrowed chords (iv in major), Neapolitan chords (bII)

Phrasal Structure and Formal Organization

• Cadence types and placement provide insights into phrasal structure and formal organization
  • PACs often indicate the end of a section or movement
  • IACs and DCs can be used to extend or develop musical ideas
• Harmonic analysis contributes to understanding the emotional or expressive impact of a composition
  • Supports or enhances melodic, rhythmic, and formal aspects

Harmonic Analysis of Compositions

Analyzing Original Works or Arrangements

• Identify the key and label chords using Roman numerals
  • Consider the quality and function of each chord within the harmonic context
• Annotate the score to indicate chord progressions, cadences, and non-diatonic chords
  • Use symbols or abbreviations (PAC, IAC, HC, DC, V/V, bVI)
• Analyze the harmonic rhythm and its interaction with melodic and rhythmic elements
  • Identify changes in harmonic rhythm and their effect on musical tension and release
• Identify recurring harmonic patterns, sequences, or motifs
  • Determine how they contribute to the overall structure and coherence of the piece

Reflecting on Harmonic Choices and Expressive Impact

• Consider the emotional or expressive impact of the harmonic choices
  • How do they support or enhance the melodic, rhythmic, and formal aspects?
• Reflect on the use of non-diatonic chords and their effect on musical tension and color
  • Secondary dominants, borrowed chords, Neapolitan chords
• Analyze the placement and types of cadences
  • How do they contribute to the phrasal structure and formal organization?
• Compare the harmonic language of the composition to other works or styles
  • Identify similarities, differences, and innovations in the use of harmony