Dodecahedron

Acousmatic tape music piece for spatialized brass ensemble by Yuval Adler, composed for Music 222 (Sound in Space) during the Spring 2017 offering.

General Idea

The main sonic element consists of twelve brasswind parts spatialized in a sphere around the listener. Instead of melodies, the musical material is mainly comprised of sound masses. Each of the twelve parts is recorded separately, and later combined into equidistant points on a sphere in 3rd order ambisonics. This piece will aim to give greater clarity to an otherwise dense musical mass of sounds by separating them in space, and to add a new dimension of progress to a piece which has no melodic changes.

Musical Form and Technical Details

1st Section

The first section of the composition reveals the twelve parts, spatialized using the AmbiX VST in Reaper DAW, in different combinations until all twelve parts are playing a dense cluster of semi-tones. The center of mass of the soundfield changes according to which parts are playing in any given moment. In the middle of this section the notes change from recordings of softer tones positioned close to the listener to recordings of louder ones positioned farther away. Instead of overall intensity, the change is conveyed through different microphone positions in recording, and different levels of reverb applied to the tracks. The wet only part of the reverb for each channel is sent to the omni (W) channel of the ambisonics mix, for an approximation of the diffuse effect.

2nd Section

In the second section the sphere of sounds goes through different spatial manipulations to focus the sounds in different areas around the audience, again moving the center of mass of the soundfield, this time as a cohesive whole that is mathematically manipulated in ambisonics. For this the Ambisonics Toolkit VST is used. Since this plug-in library uses first order ambisonics, the soundfiled is degraded to first order for this section. The different spatial manipulations are coupled with different spectral filters to articulate the spatial manipulations performed.

3rd Section

In the third section the soundfield is manipulated by having the sound sources go through an interplay of changes in portrayed distance from the listener using level and reverberation changes in the mix between them, while a subtle constant rotation is applied to the entire soundfield.

Recordings

3rd Order Ambisonics File

For listening in a proper environment that supports 3rd order ACN/SN3D ambisonics decoding and playback. Environment rendered for was relatively large and reverberant, so this version is somewhat dry for certain playback set-ups:

https://ccrma.stanford.edu/~adler/222/dodecahedron_may26_2017_bing_grail.wav

Binaural Render File

For reproduction over headphones (please be aware this render is very limited in its fidelity to the spatial component of the piece, which was a major driving force in its composition):

https://ccrma.stanford.edu/~adler/222/dodecahedron_june10_2017_binaural.wav