structural / Symbolic

Point song form

A song form reduced to non-pitch-specific shapes — section labels and order are kept, but each chord is a point-set (offsets, no key). This is the transposition-invariant structural fingerprint of a song: two songs in different keys with the same form land on the same point-song-form, so it is the natural representation for song-to-song similarity. Its `groupOf` is point-set-sequence.

How it works

Its shape has no fixed root. Choose an anchor before turning it into absolute MIDI notes.

It groups point set sequence objects in a defined order.

Written forms

Ways to write this concept

Each notation describes the same underlying object. Load a playable example to hear one MIDI realization in the Code Sequencer.

sections

Semicolon-separated `Label: progression` sections; each progression is comma-separated point-sets (offsets from each chord's root).

Verse: 0-4-7,0-3-7,0-4-7,0-3-7; Chorus: 0-3-7,0-4-7

Choose Load beside a convertible example to open its live player. Some catalog formats describe analysis or a display label and have no note realization yet.

Note Set SequenceAn ordered sequence of note sets (chords) that may contain duplicates Pc Set SequenceAn ordered sequence of pitch class sets that may contain duplicates Song formA chord progression arranged by labeled section (intro, verse, chorus, bridge…) — the harmonic skeleton of a lead sheet or guitar-chord chart. An ordered, named sequence whose sections are chord progressions (its `groupOf` is note-set-sequence). Forget the labels/order and it becomes a collection of progressions; forget pitch and it becomes a point-song-form (a key-independent structural shape for comparing songs).Pc song formA song form whose section progressions are octave-free (pitch-class) — the octaveless abstraction of a song-form. Keeps section labels, order, and harmony but drops register. Its `groupOf` is pc-set-sequence.Point sequenceAn ordered, rootless pitch contour. An anchor note turns its relative positions into a concrete line.Point scoreA key-independent polyphonic shape — simultaneous point-sequences (offset lines). The transposition-invariant fingerprint of a counterpoint: two passages in different keys with the same voice motion land on the same point-score, so it is the natural representation for contrapuntal similarity. Its `groupOf` is point-sequence.

How it works

Ways to write this concept

sections

Concept connections