Pitch Reference

This document describes how pitches are represented in MuseScore, including MIDI pitch values and Tonal Pitch Class (TPC) values.

Source Files

• docs/pitch.md
• docs/tpc.md

MIDI Pitch Values

Note pitches are internally expressed with their respective MIDI pitch values (0-127). This corresponds to the absolute height of the note, regardless of enharmonic spelling.

Pitch Table by Octave

Note: Middle C (C4) = 60

Common Reference Pitches

Pitch Calculation Formula

// Calculate pitch from note name and octave
function pitchFromNote(noteName, octave) {
    var noteOffsets = {
        'C': 0, 'D': 2, 'E': 4, 'F': 5, 'G': 7, 'A': 9, 'B': 11
    };
    return (octave + 1) * 12 + noteOffsets[noteName.toUpperCase()];
}

// Examples:
pitchFromNote('C', 4);  // 60 (Middle C)
pitchFromNote('A', 4);  // 69 (Concert A)
pitchFromNote('G', 3);  // 55

// Convert pitch to note name
function noteFromPitch(pitch) {
    var noteNames = ['C', 'C#', 'D', 'D#', 'E', 'F', 'F#', 'G', 'G#', 'A', 'A#', 'B'];
    var octave = Math.floor(pitch / 12) - 1;
    var noteName = noteNames[pitch % 12];
    return noteName + octave;
}

// Examples:
noteFromPitch(60);  // "C4"
noteFromPitch(69);  // "A4"

Tonal Pitch Class (TPC)

The TPC differentiates between notes with the same MIDI pitch but different enharmonic spellings (e.g., C# vs Db).

TPC Values by Note Name

TPC Pattern

The TPC follows the circle of fifths pattern:

• Natural notes: 13-19 (F, C, G, D, A, E, B)
• Single flat: 6-12 (Fb, Cb, Gb, Db, Ab, Eb, Bb)
• Double flat: -1 to 5 (Fbb, Cbb, Gbb, Dbb, Abb, Ebb, Bbb)
• Single sharp: 20-26 (F#, C#, G#, D#, A#, E#, B#)
• Double sharp: 27-33 (F##, C##, G##, D##, A##, E##, B##)

TPC and Pitch Relationship

Working with TPC

// Access note TPC
var note = cursor.element.notes[0];
console.log("TPC: " + note.tpc);
console.log("TPC1 (concert): " + note.tpc1);
console.log("TPC2 (transposing): " + note.tpc2);

// Common TPC values for reference
var TPC = {
    // Natural notes
    C: 14, D: 16, E: 18, F: 13, G: 15, A: 17, B: 19,

    // Single sharps
    Cs: 21, Ds: 23, Es: 25, Fs: 20, Gs: 22, As: 24, Bs: 26,

    // Single flats
    Cb: 7, Db: 9, Eb: 11, Fb: 6, Gb: 8, Ab: 10, Bb: 12
};

Note Properties

When working with notes, these properties are available:

var note = cursor.element.notes[0];

// Read properties
var pitch = note.pitch;      // MIDI pitch (0-127)
var tpc = note.tpc;          // Tonal pitch class
var tpc1 = note.tpc1;        // TPC in concert pitch
var tpc2 = note.tpc2;        // TPC in transposing pitch

// Modify properties
curScore.startCmd("Change Pitch");
note.pitch = 62;             // Change to D
note.tpc1 = 16;              // Set TPC to D natural
note.tpc2 = 16;              // Same for transposing
curScore.endCmd();

Key Signature Values

Key signatures use the number of accidentals:

• Negative values = flats
• Zero = C major / A minor
• Positive values = sharps

// Get key signature
var keySig = cursor.keySignature;  // Number of sharps/flats

// Key signature names
var keyNames = {
    '-7': 'Cb major',
    '-6': 'Gb major',
    '-5': 'Db major',
    '-4': 'Ab major',
    '-3': 'Eb major',
    '-2': 'Bb major',
    '-1': 'F major',
    '0': 'C major',
    '1': 'G major',
    '2': 'D major',
    '3': 'A major',
    '4': 'E major',
    '5': 'B major',
    '6': 'F# major',
    '7': 'C# major'
};

Example: Transposing Notes

function transposeSelection(semitones) {
    var selection = curScore.selection;
    if (!selection) return;

    curScore.startCmd("Transpose");

    var elements = selection.elements;
    for (var i = 0; i < elements.length; i++) {
        var el = elements[i];
        if (el.type == Element.NOTE) {
            el.pitch += semitones;
            // Note: TPC may need adjustment for proper spelling
        }
    }

    curScore.endCmd();
}

// Transpose up a perfect fifth (7 semitones)
transposeSelection(7);

// Transpose down an octave (12 semitones)
transposeSelection(-12);

Example: Building Chords by Pitch

// Build a major chord from root pitch
function addMajorChord(cursor, rootPitch) {
    curScore.startCmd("Add Major Chord");
    cursor.addNote(rootPitch, false);      // Root
    cursor.addNote(rootPitch + 4, true);   // Major 3rd (+4 semitones)
    cursor.addNote(rootPitch + 7, true);   // Perfect 5th (+7 semitones)
    curScore.endCmd();
}

// Build a minor chord
function addMinorChord(cursor, rootPitch) {
    curScore.startCmd("Add Minor Chord");
    cursor.addNote(rootPitch, false);      // Root
    cursor.addNote(rootPitch + 3, true);   // Minor 3rd (+3 semitones)
    cursor.addNote(rootPitch + 7, true);   // Perfect 5th (+7 semitones)
    curScore.endCmd();
}

// Build a dominant 7th chord
function addDom7Chord(cursor, rootPitch) {
    curScore.startCmd("Add Dom7 Chord");
    cursor.addNote(rootPitch, false);      // Root
    cursor.addNote(rootPitch + 4, true);   // Major 3rd
    cursor.addNote(rootPitch + 7, true);   // Perfect 5th
    cursor.addNote(rootPitch + 10, true);  // Minor 7th (+10 semitones)
    curScore.endCmd();
}

// Usage
addMajorChord(cursor, 60);  // C major chord
addMinorChord(cursor, 69);  // A minor chord
addDom7Chord(cursor, 55);   // G7 chord