Introduction to Pure Data by Andy Farnell

Pure Data is a visual environment for programming sound. Andy uses it for sound design and for teaching purposes. He finds it a very useful tool to teach secondary school students and PhD students. It allows to mock up ideas very quickly, faster than by using programming languages such as C++.

Andy is the author of the excellent book Designing Sound, available from MIT Press and other online distributors. It’s a great way to get into Pure Data and programmatic sound design. More about Andy on his website.

Andy Farnell at the Hackspace

It is also easier to access and understand. In the patch below, the ‘noise~’ object generates white noise (the sound of your aerial TV when there’s no channel available). This white noise is sent to an amplifier, the ‘*~’ object. This object allows to control the volume of the sound using the number box above it. The white noise is then sent to the speakers via an Digital Analog Converter (the ‘dac~’ object). It’s that simple.

A PD patch to make noise

It’s also easy, if you want to use a MIDI controller, to allow MIDI notes in your patch. In the patch below, we use the object ‘notin’ which allows MIDI messages to be connected to something.The notes are converted to frequency with the object ‘mtof’ (Midi TO Frequency). The value is then sent to a ‘phasor~’ object which generates a sawtooth signal, then sent to the dac.

A basic synthesizer in PD

Ariel was using his computer to learn PD during the session and we connected his computer to Anduy’s computer using OSC through the wifi network. There was a wooow moment when a ‘bang’ was sent from Andy’s computer and showed up in Ariel’s console. Now they’re working on making a sampler over the network!

This is the result of it. Ariel controls the volume of the sample from his computer.

Collaborative PD patch controlled by a remote computer

To Ziad’s request, Andy ¬†gave us an introduction to sequencing. In the patch below, the ‘metro’ sends a ‘bang’ which is delayed at 4 different time values to create a pattern.

An improvised four-step sequencer

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