Cadence Type Classifier

Classify supplied Roman-function pair with both root-bass and final soprano evidence under elementary authentic/plagal/half/deceptive conventions; authentic tonic must be a triad, no phrase-boundary inference or automatic audio analysis.

Description

Cadence labels combine a chord-function pair with bass and soprano evidence.

Cadence labels combine a chord-function pair with bass and soprano evidence. Perfect authenticity requires more than a V–I pair.^[1]

Enter two exact Roman tokens and three evidence booleans. Apply authentic first, then IV/iv→I/i plagal, final majorV half, and V→VI/vi deceptive checks; otherwise unrecognized.

When to use Cadence Type Classifier

Use Cadence Type Classifier when you need to evaluate the supplied records under the calculation and evidence rules below. Final authentic/plagal tonic must lack a seventh. No phrase boundary, audio function or broader style convention 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 Cadence Type Classifier 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 penultimateRomanChord, finalRomanChord, penultimateRootInBass, finalTonicRootInBass, finalSopranoOnTonic using the field table and calculation rules, then run the tool.
Read cadenceLabel, recognizedFunctionalCadence. 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
penultimateRomanChord	Penultimate roman chord	string	Required
finalRomanChord	Final roman chord	string	Required
penultimateRootInBass	Penultimate root in bass	boolean	Required
finalTonicRootInBass	Final tonic root in bass	boolean	Required
finalSopranoOnTonic	Final soprano on tonic	boolean	Required

Enter two exact Roman tokens and three evidence booleans. Apply authentic first, then IV/iv→I/i plagal, final majorV half, and V→VI/vi deceptive checks; otherwise unrecognized.

authentic=V→I/i triad; perfect additionally requires both root basses and final tonic soprano

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

Output field	Meaning	Value type
cadenceLabel	Cadence label	string
recognizedFunctionalCadence	Recognized functional cadence	boolean

json

{
  "input": {
    "penultimateRomanChord": "V7",
    "finalRomanChord": "I",
    "penultimateRootInBass": true,
    "finalTonicRootInBass": true,
    "finalSopranoOnTonic": true
  },
  "output": {
    "cadenceLabel": "perfect-authentic",
    "recognizedFunctionalCadence": true
  }
}

Limitations and assumptions

Final authentic/plagal tonic must lack a seventh. No phrase boundary, audio function or broader style convention 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. A successfully returned false flag is an evaluated outcome; its meaning is explained above.

Alternative or Complementary methods

Use Roman Numeral Chord Analysis: Roman analysis preserves a chord root’s written degree and chromatic alteration. Enharmonic sounding equality can conceal different written functions. For a complementary task, use Voice-Leading Motion Classifier: Two-voice motion distinguishes direction from interval size. Crossing requires reversal of the voices’ relative pitch order.

References

Cadence Type Classifier — tool.io

Similar or alternative tools

Roman Numeral Chord Analysis
Roman analysis preserves a chord root’s written degree and chromatic alteration. Enharmonic sounding equality can conceal different written functions.
Voice-Leading Motion Classifier
Two-voice motion distinguishes direction from interval size. Crossing requires reversal of the voices’ relative pitch order.