Tools

12-Tone Row Generator

Generate a random twelve-tone row and inspect Prime, Inversion, Retrograde, and Retrograde Inversion forms.

Generate and hear every row form

12-Tone Row Generator

Create a twelve-tone row, inspect its prime, inversion, retrograde, and retrograde-inversion forms, then set register, duration, and BPM for playback or MIDI export.

Create the row before exploring its forms

  1. Enter or generate an original row and choose its starting register.
  2. Compare P, I, R, and RI forms before changing playback settings.
  3. Play the complete row or export the selected forms as MIDI.
P₀ I₀ R₀ RI₀
Understand the twelve-tone row

A twelve-tone row presents all 12 pitch classes without repetition. It avoids tonal hierarchy and forms the basis for serial composition.

Current prime row

Prime row score

Read the generated prime row in OSMD notation.
Naming context
C
Range and playback
Rhythm
Key
C
Signature
—
Ready.
Transport
Export and copy

Prime

P₀

The original ordered row.

Inversion

I₀

Intervals are mirrored around the first pitch.

Retrograde

R₀

The row played backward.

Retrograde inversion

RI₀

The inversion played backward.

Twelve-tone matrix

All transpositions of the row and its inversion.

Selected matrix form

Selected form controls

Advanced row analysis

Verified musical example

Twelve-tone technique: from matrix to composition

Pitch classes, aggregate and row

A twelve-tone row is an ordered succession of the twelve pitch classes C=0 through B=11 in equal temperament. Pitch class is octave-equivalent: C3, C4 and C5 share the same integer.

A row is not a chromatic scale. The chromatic aggregate says that all twelve classes are present; the row adds a specific order that can be transformed, partitioned and composed with.

Historical and stylistic context

Schoenberg systematized twelve-tone technique after free atonality; Webern explored compression, symmetry and timbre; Berg combined rows with dramatic, tonal and expressive references.

Pitch serialism is not the same as integral serialism. Later composers extended serial thinking to rhythm, dynamics and timbre, but no single procedure defines every twelve-tone composition.

P, I, R and RI

P keeps the row order. I reflects every pitch class around an axis a with I_a(p)=(2a-p) mod 12. R reverses P, and RI reverses I.

JolyMusic labels matrix rows by transposition level relative to the first row head, and columns by the corresponding inversion-column head. The inversion convention is pitch-class-axis reflection.

Reading the matrix

The first row is the generated prime row. The first column is its inversion fixing the initial pitch class. Horizontal reading gives P forms; reverse horizontal reading gives R forms.

Vertical reading gives I forms; reverse vertical reading gives RI forms. Labels identify the transposition level of the form being read, not an index in the visual table.

From row to composition

The row constrains pitch organization, not every musical parameter. Register, rhythm, dynamics, articulation, instrumentation, texture and phrase structure remain compositional choices.

Local repetitions, doublings, trills or sustained tones can appear in real music; the analytical question is how they relate to the abstract row statement.

Progressive exercises

1. Identify twelve distinct pitch classes

Source: Use the current row.

Instructions: Check that every integer 0-11 appears once.

Expected result: Twelve unique classes.

Musical interpretation: You have a complete chromatic aggregate.

Success criterion: No duplicate or missing class remains.

2. Construct a valid row

Source: 0 1 4 2 7 5 9 6 11 8 3 10

Instructions: Enter or compare the sequence as P.

Expected result: A valid ordered aggregate.

Musical interpretation: The order creates motivic identity.

Success criterion: Validation reports twelve unique classes.

3. Calculate a retrograde

Source: The example row.

Instructions: Read P from right to left.

Expected result: 10 3 8 11 6 9 5 7 2 4 1 0.

Musical interpretation: Contour order is reversed.

Success criterion: Your R matches the displayed retrograde.

4. Calculate an inversion

Source: The example row around C=0.

Instructions: Apply (2a-p) mod 12 to each pitch class.

Expected result: 0 11 8 10 5 7 3 6 1 4 9 2.

Musical interpretation: Directed intervals are mirrored.

Success criterion: Your I0 matches the verified example.

5. Calculate a retrograde inversion

Source: The example inversion.

Instructions: Reverse the inversion sequence.

Expected result: 2 9 4 1 6 3 7 5 10 8 11 0.

Musical interpretation: The mirror is heard backward.

Success criterion: Your RI0 matches the verified example.

6. Read forms from the matrix

Source: Current matrix.

Instructions: Select one row and one column, then compare forward and reverse reading.

Expected result: One P/R pair and one I/RI pair.

Musical interpretation: The same table supplies all four families.

Success criterion: The selected labels match the highlighted form.

7. Compare row segments

Source: First two trichords.

Instructions: Compare prime forms and interval-class vectors.

Expected result: A set-theory comparison rather than a melodic interval list.

Musical interpretation: Segments can become motives or harmonies.

Success criterion: You distinguish ordered intervals from interval classes.

8. Compose a short phrase

Source: Any P form plus a related I or R form.

Instructions: Assign register, rhythm and articulation to two forms.

Expected result: A two-phrase sketch using related row forms.

Musical interpretation: The row organizes pitch while musical parameters create shape.

Success criterion: The phrase uses the selected forms consistently.

Generate and hear every row form

From a row to a playable twelve-tone study

Generate the prime row

The original row is the source for every displayed form; preserve its order when comparing transformations.

Read inversion and retrograde

Register, note length, and BPM affect the playable result without changing the pitch-class logic of the row.

Sing one form before comparing another

  • Enter or generate an original row and choose its starting register.
  • Compare P, I, R, and RI forms before changing playback settings.
  • Play the complete row or export the selected forms as MIDI.

Export the row or develop it with counterpoint