Major Scale Pattern Checker

Audit ordered seven successive steps including octave closure against major W W H W W W H, retaining mismatch locations and actual span; no rotation inference or generated scale alias.

Description

The major scale has seven ordered steps including the return to the octave.

The major scale has seven ordered steps including the return to the octave. Correct membership alone does not verify this ordered pattern.^[1]

Enter exactly seven integer semitone steps 1–12. Compare each with the expected pattern; return match, total span and zero-based mismatches.

When to use Major Scale Pattern Checker

Use Major Scale Pattern Checker when you need to evaluate the supplied records under the calculation and evidence rules below. The octave span can differ from 12 when false. No rotations, tonic, spelling or scale generation are 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 Major Scale Pattern Checker 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 ascendingOctaveStepSemitones using the field table and calculation rules, then run the tool.
Read matchesMajorPattern, observedOctaveSpanSemitones, mismatchingStepIndices. 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
ascendingOctaveStepSemitones	Ascending octave step semitones	list of number	Required

Enter exactly seven integer semitone steps 1–12. Compare each with the expected pattern; return match, total span and zero-based mismatches.

expected=[2,2,1,2,2,2,1]; span=sum(observed)

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

Output field	Meaning	Value type
matchesMajorPattern	Matches major pattern	boolean
observedOctaveSpanSemitones	Observed octave span semitones	number
mismatchingStepIndices	Mismatching step indices	list of number

json

{
  "input": {
    "ascendingOctaveStepSemitones": [
      2,
      2,
      1,
      2,
      2,
      2,
      1
    ]
  },
  "output": {
    "matchesMajorPattern": true,
    "observedOctaveSpanSemitones": 12,
    "mismatchingStepIndices": []
  }
}

Limitations and assumptions

The octave span can differ from 12 when false. No rotations, tonic, spelling or scale generation are inferred.

Numeric inputs, where present, must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Numeric lists are limited to 10,000 entries; string lists to 128 strings of at most 128 characters each. The rules above may impose smaller limits. 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 Mode From Major Scale Degree Lookup: Modes rotate a parent major collection without changing its pitches. The new tonic and ordered steps are determined by the starting degree. For a complementary task, use Whole-Tone Scale Generator: A whole-tone collection contains six pitch classes separated by two semitones. Written note letters preserve a chosen scale spelling.

References

Major Scale Pattern Checker — tool.io

Similar or alternative tools

Mode From Major Scale Degree Lookup
Modes rotate a parent major collection without changing its pitches. The new tonic and ordered steps are determined by the starting degree.
Whole-Tone Scale Generator
A whole-tone collection contains six pitch classes separated by two semitones. Written note letters preserve a chosen scale spelling.