Roman Numeral Chord Analysis

Analyze caller spelled root and explicit tertian quality relative to major tonic, retaining diatonic enharmonic distinction and seventh suffix; no harmonic-function inference from audio or inversion.

Description

Roman analysis preserves a chord root’s written degree and chromatic alteration.

Roman analysis preserves a chord root’s written degree and chromatic alteration. Enharmonic sounding equality can conceal different written functions.^[1]

Enter pitch-class major tonic/root and supported major/minor/diminished/augmented triad or major/dominant/minor/half-diminished/diminished seventh quality. Return altered Roman label, degree and alteration within ±2.

When to use Roman Numeral Chord Analysis

Use Roman Numeral Chord Analysis when you need to evaluate the supplied records under the calculation and evidence rules below. Case and suffix encode the supplied quality. No audio, bass, inversion or harmonic intention is inferred.

Enter the written notes, explicit grouping, pitch observations or supported chord tokens requested. Keep scientific octaves, accidentals and caller evidence consistent.

How to use Roman Numeral Chord Analysis and understand its results

Enter the written notes, explicit grouping, pitch observations or supported chord tokens requested. Keep scientific octaves, accidentals and caller evidence consistent.
Enter majorTonic, chordRoot, chordQuality using the field table and calculation rules, then run the tool.
Read romanAnalysis, diatonicRootDegree, rootChromaticAlteration. The explanation below defines the units, signs, ordering and any flags or placeholder values.
If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.

Input field	Meaning	Value type; see rules below	Requirement
majorTonic	Major tonic	string	Required
chordRoot	Chord root	string	Required
chordQuality	Chord quality	string	Required

degree=letter displacement+1; alteration=signed class difference from major degree

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
romanAnalysis	Roman analysis	string
diatonicRootDegree	Diatonic root degree	number
rootChromaticAlteration	Root chromatic alteration	number

json

{
  "input": {
    "majorTonic": "C",
    "chordRoot": "Eb",
    "chordQuality": "major"
  },
  "output": {
    "romanAnalysis": "bIII",
    "diatonicRootDegree": 3,
    "rootChromaticAlteration": -1
  }
}

Limitations and assumptions

Case and suffix encode the supplied quality. No audio, bass, inversion or harmonic intention is inferred.

Numeric inputs, where present, must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Extremely large text inputs are rejected. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.

Alternative or Complementary methods

Use Nashville Number System Conversion: Nashville numbers express degree and quality through a declared text convention. A dominant seventh combines its degree digit with a seventh suffix. For a complementary task, use Secondary Dominant Target Lookup: A secondary dominant is spelled a perfect fifth above a declared target. The slash target carries Roman degree and alteration relative to a major tonic.

References

Roman Numeral Chord Analysis — tool.io

Similar or alternative tools

Nashville Number System Conversion
Nashville numbers express degree and quality through a declared text convention. A dominant seventh combines its degree digit with a seventh suffix.
Secondary Dominant Target Lookup
A secondary dominant is spelled a perfect fifth above a declared target. The slash target carries Roman degree and alteration relative to a major tonic.