Spatial Dramaturgy Composer - Compositional Spatial Form

Compose large-scale spatial behaviour from musical form. A dramaturgical curve drives spread, distance, movement, instability, elevation, peripheralisation, and fragmentation, while the script derives the trajectories and renders the result offline.

Author: Shai Cohen Affiliation: Department of Music, Bar-Ilan University, Israel Version: 1.2 (2026) Category: Spatial & Surround License: MIT License Repo: Praat AudioTools

Contents:

What this does Quick start Main controls Dramaturgy sources Analyze Source Spatial dimensions Custom mapping Spatial strategies Fragmentation Output formats Visualisation Output Performance Limitations Musical use

What this does

Spatial Dramaturgy Composer treats space as part of musical form rather than as a sequence of manually drawn pan positions. A normalized dramaturgical curve D(t) from 0 to 1 controls seven spatial dimensions, from focus and distance to motion, elevation, and fragmentation.

dramaturgical form → spatial state → trajectories → multichannel sound

You shape the large-scale spatial behaviour; the script derives the detailed trajectories. This makes it possible to compose forms such as intimacy → expansion → fragmentation → collapse without drawing every path by hand.

Quick start

Select exactly one Sound in Praat. You may also select one RealTier if you want to use it as a drawn dramaturgical curve.
Run Spatial_Dramaturgy_Composer.praat.
Choose Draw, Analyze source, or Archetype.
Choose a Spatial strategy, Character, and output format.
Enable Show details only when you want to edit analysis weights, fragmentation, custom mappings, or output settings.

Main controls

Control	Default	What it changes
Dramaturgy	Archetype	Choose a drawn curve, automatic source analysis, or a predefined macro-form.
Archetype	Arch	Select one of 14 large-scale dramaturgical shapes.
Spatial strategy	Auto	Determines how dramaturgy is translated into spatial behaviour.
Character	Dramatic	Controls the overall strength of the spatial transformation: Subtle, Moderate, Dramatic, or Radical.
Output	8-channel ring	Stereo, Quad, 8-channel ring, custom speaker ring, or first-order Ambisonics.
Max agents	4	Sets the maximum number of independently moving spatial layers.
Random seed	30217	Lets stochastic motion be reproduced exactly.
Draw visualisation	On	Draws the dramaturgy and spatial evolution in the Praat Picture window.
Play result	On	Plays the rendered Sound after processing.

Dramaturgy sources

Draw

Use a RealTier as the dramaturgical curve, or let the script create a starter curve that you can edit before rendering.

Analyze source

Derives the dramaturgical curve from changes in the sound itself, using weighted acoustic features and smoothing.

Archetype

Uses a predefined large-scale shape. Archetype strength controls how strongly the shape is expressed.

Auto strategy

Chooses a spatial strategy suited to the selected archetype. Drawn and analyzed curves use a general expressive mapping by default.

Available archetypes

Expansion · Implosion · Arch · Inverted Arch · Ascent · Descent · Encirclement · Fragmentation · Convergence · Dissolution · Accumulation · Shock · Waves · Chaotic Escalation.

Analyze Source

Analyze Source creates a dramaturgical curve from several acoustic cues. You can adjust their weights in Show details.

Descriptor	Default weight	Musical role
Intensity	1.0	Energetic level.
Spectral brightness	0.7	Dark-to-bright spectral movement.
Spectral change	0.8	Amount of timbral change over time.
Activity density	0.6	Density of local activity and attacks.
Noisiness	0.4	Noise-like versus harmonic character.
Pitch instability	0.0	Optional local F0 variation; useful mainly for pitched material.

Interpretation: the analysis is source-relative. It follows where a sound becomes more or less active, bright, changing, noisy, or unstable within that file; it is not an absolute measure of perceived musical tension.

The seven spatial dimensions

Dimension	Low value	High value
Spread	Focused / point-like	Wide spatial dispersion
Distance	Near	Far
Movement rate	Static	Fast motion
Irregularity	Smooth / stable	Unstable / stochastic
Elevation	Horizontal / low	Elevated
Peripheralisation	Front / centre	Sides / rear
Fragmentation	One coherent source	Several spatial agents

Custom mapping

In Custom mapping, each spatial dimension can have its own range, direction, response curve, and influence. This is useful when you want a very specific relationship between dramaturgy and space.

min max direction curve influence

Example:

0.05 0.95 + sig 1

Direction can be +, -, or =. Available response curves are lin, exp, log, sig, thr, step, and rnd.

A climax does not have to become wider or more active. You can invert any mapping so that increasing dramaturgy produces contraction, stillness, or convergence instead.

Spatial strategies

Intimate to Overwhelming · Compression · Explosion · Breathing Space · Orbiting Tension · Fragmented Climax · Frozen Climax · Vertical Drama · Peripheral Anxiety · Dissolution · Swarm · Radical · Custom mapping.

These strategies are starting points rather than fixed aesthetics. Character and detailed mappings let you make the same dramaturgical curve subtle, extreme, expanding, contracting, mobile, or nearly static.

Fragmentation

When fragmentation rises, the sound can separate into several spatial agents rather than remaining one coherent moving source. Three methods are available:

Frequency bands

Different spectral regions become independent spatial agents. This is the default method.

Temporal slices

Different time slices are distributed among moving agents, producing a more articulated spatial breakup.

Delayed copies

Short delayed versions of the source create a denser, more diffuse spatial image. Tonal material may acquire additional phase coloration.

Output formats

Speaker outputs

Stereo, Quad, 8-channel ring, and custom 3-32 speaker rings use amplitude spatialisation. Stereo is a left/right projection, so front and rear positions cannot remain distinct.

First-order Ambisonics

FOA output is encoded as AmbiX, ACN W Y Z X, SN3D. It requires an Ambisonic decoder for loudspeaker or binaural playback.

Distance and elevation

Distance changes apparent level and diffuseness; it does not simulate physical propagation, air absorption, or Doppler effects. Elevation is represented directly in FOA. Horizontal speaker rings cannot reproduce true height.

Level management

The default output normalization targets a peak of -1 dBFS while preserving the balance between channels. You can also leave the level unchanged with clipping protection.

Visualisation: the spatial score

The Picture-window display shows how the dramaturgical curve becomes spatial behaviour.

Dramaturgy D(t): the large-scale control curve.
Spatial dimensions: spread, distance, movement rate, irregularity, elevation, peripheralisation, and fragmentation.
Agent trajectories: azimuth movement through time.
Field from above: top-down view of the evolving spatial image.
Routing gain map: a fast view of how the renderer distributes energy among output channels.
Measured output energy: an optional, slower RMS-based diagnostic.

Output

The script creates the final rendered multichannel Sound and leaves the original source unchanged.

If you supply your own RealTier as the dramaturgical curve, it is preserved. Multichannel input is averaged to mono before the new spatial image is created.

Performance

Long rendering times are normal. Processing becomes slower with longer source files, more output channels, and more spatial agents.

If you want a faster first test, use a short excerpt, fewer agents, or a smaller output layout. The optional measured-energy visualisation also adds extra processing.

Limitations

Rendering is offline, not real-time.
Speaker modes use amplitude spatialisation rather than physical room or propagation simulation.
Horizontal speaker rings cannot reproduce true elevation.
FOA output is encoded but not decoded inside the script.
Analyze Source is a compositional, source-relative estimator rather than an absolute model of perceived tension.

Musical use

Examples of large-scale spatial forms include:

focus → expansion → fragmentation → saturation → collapse
diffusion → convergence → stillness
frontality → encirclement → elevation → disappearance

The central idea is simple: space can carry musical form rather than merely display it.