Class Schenker

Basic Schenkerian reduction (approximate): Urlinie, Ursatz and structural levels of a progression.

Index

Constructors

Methods

findUrlinie getUrsatz prolongationLevel

Constructors

constructor

new Schenker(): Schenker
Returns Schenker

Methods

`Static`findUrlinie

findUrlinie(melody: Note[], keySymbol: string): UrlinieResult | null
Attempts to identify an Urlinie (fundamental melodic line) in a melody.

Looks for a descending stepwise line ending on the tonic that covers a 3rd (^3-^2-^1), 5th (^5-^4-^3-^2-^1), or octave (^8-^7-...-^1).

Returns null if no clear Urlinie is detected.
Parameters
- melody: Note[]
  Melody notes (12-TET).
- keySymbol: string
  Key, e.g. 'C major'.
Returns UrlinieResult | null
- Defined in schenker.ts:38

`Static`getUrsatz

getUrsatz(
    progression: Chord[],
    melody: Note[],
    keySymbol: string,
): { bass: Note[]; melody: Note[] } | null
Identifies an Ursatz (basic structure) from a progression and melody. Returns the bass arpeggiation (I-V-I) and Urlinie notes, or null.
Parameters
- progression: Chord[]
- melody: Note[]
- keySymbol: string
Returns { bass: Note[]; melody: Note[] } | null
- { bass: Note[]; melody: Note[] }
  - bass: Note[]
    Roots of the bass arpeggiation I-V-I found in the progression (two or three notes).
  - melody: Note[]
    The Urlinie (see findUrlinie).
- null
- Defined in schenker.ts:83

`Static`prolongationLevel

prolongationLevel(
chords: Chord[],
level: "foreground" | "middleground" | "background",
): Chord[]
Reduces a chord progression to a simplified structural level.
- 'background': only tonic and dominant (the first chord is taken as the tonic).
- 'middleground': merges consecutive chords on the same root (C C7 → C).
- 'foreground': merges consecutive identical chords (same pitch classes).
Parameters
- chords: Chord[]
- level: "foreground" | "middleground" | "background"
Returns Chord[]
- Defined in schenker.ts:129