structural / Symbolic

Song form

A 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).

How it works

This object can carry concrete values or a musical interpretation, depending on its notation.

It groups note set sequence objects in a defined order.

Written forms

Ways to write this concept

Each notation describes the same underlying object. Open an example to see it in every other notation, or load it to hear one MIDI realization in the Code Sequencer.

sections

Open guide

Canonical: semicolon-separated `Label: progression` sections; each progression is a comma-separated chord chart. Repeats are allowed (a chorus can recur).

midi sections

Same structure with MIDI chord sets: `Label: set,set,…` where a set is dash-joined MIDI numbers.

Verse: 60-64-67,67-71-74,57-60-64,53-57-60; Chorus: 53-57-60,60-64-67

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.

Pc Set SequenceAn ordered sequence of pitch class sets that may contain duplicates Point Set SequenceAn ordered sequence of point-sets that may contain duplicates 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 song formA 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.Note sequenceAn ordered line of notes and optional rests. Adding durations makes its rhythmic placement explicit.ScoreA polyphonic texture — several voices (temporalized lines / tracks) sounding at once over a shared timeline. The simultaneous counterpart of a note-set: where a note-set stacks single notes into a chord, a score stacks whole lines. Its `groupOf` is note-sequence. Collapse the voices at each instant and you get a chord progression (note-set-sequence) — the resulting chord qualities of the simultaneous notes; conversely, a chord progression can be voice-led into a score. Strip pitch and it becomes a point-score (key-independent counterpoint).

How it works

Ways to write this concept

sections

midi sections

Concept connections