Interactive Pitch Class Calculator
Convert note names, pitch numbers, and pitch-class sets instantly. Great for music theory classes, composition, analysis, and ear-training practice.
1) Single Note / Number
Accepted note forms: C D E F G A B with accidentals (#, b, x), optional octave. Numeric input is normalized mod 12.
2) Pitch-Class Set Analyzer
Use commas or spaces. You can mix notes and numbers in the same set.
What is a pitch class?
A pitch class groups together all notes that share the same letter-and-accidental identity across octaves. In 12-tone equal temperament, pitch classes are represented with integers 0–11. For example, C4, C5, and C2 are all pitch class 0.
This is powerful because it lets you analyze harmony and melody structurally, without getting distracted by register (high vs. low). Once everything is mapped mod 12, transposition and pattern recognition become much easier.
Standard mapping (integer notation)
- 0 = C
- 1 = C♯ / D♭
- 2 = D
- 3 = D♯ / E♭
- 4 = E
- 5 = F
- 6 = F♯ / G♭
- 7 = G
- 8 = G♯ / A♭
- 9 = A
- 10 = A♯ / B♭
- 11 = B
How to use this calculator
Single note mode
Type a note like Eb4, C#, or B## and the tool returns its normalized pitch class. If you type a number (for example 61), the calculator reduces it modulo 12 and gives the pitch class result.
Set analyzer mode
Enter a collection of notes or integers to inspect a chord or motive. The analyzer returns:
- Parsed pitch classes
- Unique set in entry order
- Sorted unique set (normal numeric ordering)
- Transposed result using your Tn value
- Interval-class vector (IC1–IC6)
Why pitch-class thinking matters
Pitch classes are central in post-tonal theory, jazz reharmonization, film scoring analysis, and algorithmic composition. They help you answer questions like:
- Are two chords transpositionally related?
- How symmetric is this collection?
- What interval content defines this sonority?
- How can I transform this set while preserving structure?
Quick examples
Example 1: Single note
Input: Db5 → output pitch class: 1 (enharmonic with C♯).
Example 2: Numeric note
Input: 73 → 73 mod 12 = 1.
Example 3: Set transposition
Input set: C, Eb, G, B = {0,3,7,11}. Apply T5 → {5,8,0,4}, which sorted is {0,4,5,8}.
FAQ
Do octaves affect pitch class?
No. Octave labels are ignored for pitch-class identity.
Can I mix note names and numbers in one set?
Yes. The analyzer accepts mixed input and normalizes everything into 0–11.
What about enharmonic spelling?
Enharmonic notes map to the same pitch class (e.g., C♯ and D♭ both map to 1). The calculator displays both sharp and flat labels for clarity.
Final thoughts
If you work with composition, arranging, improvisation, or analysis, a fast pitch class calculator saves time and reduces errors. Use it to check ideas quickly, compare chord structures, and experiment with transposition in a systematic way.