Tutorial – granulation

“All sound is an integration of grains, of elementary sonic particles, of sonic quanta…All sound, even continuous musical variation, is conceived as an assemblage of a large number of elementary sounds adequately disposed in time.”

xenakis_formalized_1992

Granular approach to processing sound was proposed by the physicist Dennis Gabor. His thinking was much along the same lines as Fourier’s proposition that all sound can be described in a certain way. In Fourier’s case, the proposition is that any signal can be described in terms of discrete sine waves, all added together with differing phase positions and amplitudes. This is aligned with a reading of the universe of sound as being wave-like. Gabor’s proposal is that we can regard the universe of sound as being composed of sonic quanta or particles and that any sound can be synthesised or created by organising the quanta in specific ways.

In reality both approaches have limitations, even amongst the ultrafast computers we have access to, but they both offer extremely interesting options to the sonic artist.

Today we focus on a particular granulation technique: time-based granulation of sampled sound.

To do this we’ll need a number of important tools:

• a grain window or envelope
• a buffer to store sound
• a way of playing back sound from the buffer and applying the window
• a way of moving around the playhead within the buffer
• a way of controlling multiple parameters to give variety and variation
• a way of making sure that you can do this multiple times, so you have multiple copies

Some helpful starting points are below. We’ll use these prefabricated materials to get us moving quickly, you can explore the prefabs in your own time after the tutorial.