The GMS (Gestural Music Sequencer), written in Processing.org by Unearthed Music recording artist and AudioCookbook.org founder John Keston, analyzes video input and converts it into a sequence of musical information in real-time. Each frame is processed to find the brightest pixel. The x coordinate is converted into pitch while the y coordinate is translated into dynamics. The application was also designed to use probability distributions on pitch and durations.
Here’s another glitch created with the GMS running at an unreasonably high tempo. This time it sounds a bit like the racket that comes from an acoustic modem as it makes a connection. Remember those things that people used to use to log on to the internets?
This eight minute segment of audio generated by the GMS is from the first eight minutes of our most recent MAW (minneapolisartonwheels.org) outing.
This was my first chance to take advantage of the presets feature, but the performance led me to expand the octave setting to include adjustments for the top and bottom octaves. During this performance the octave setting was limited to only allowing the top octave to be lowered. This made it so that instruments with a limited range, like drums, are difficult to play since much of the screen might be inactive.
The latest feature I have added to the GMS is a way to store ten presets. Each preset holds thirty-four distinct settings including all twelve note probability values, all seven duration probability values, note probabilities on/off, duration probabilities on/off, sustain on/off, free time mode vs bpm, dotted notes on/off, video mirroring on/off, tempo in BPM, note durations, transposition, scale, MIDI out channel, dotted note probabilities, note randomness, and octave range minimum and maximum. The presets can be changed by clicking a radio button, or pressing control plus the preset number. This feature makes it possible to instantly and dramatically change the behavior of the GMS. I also added a primitive save and load feature to mantain the content of the presets. Here’s a segment from a test recording.
As I spend virtually every spare moment working on the GMS I’m looking forward to slowing down the development of this sequencer so I can start using it effectively, but for now I’m happy to create the odd glitch or space pad here and there. Here’s a glitchy segment of sound created by classic, channel ten drums at high speed.
This electrical crackling sound was made with the GMS while the tempo was set quite high and the note duration probability distributions were set to favor two adjacent values. The speed that the notes were played made the frequency of playing the notes more audible than the pitch of the individual sounds themselves. The randomized durations at that speed created a sputtering quality that, to my ear, sounds very similar to high voltage electrical sparks. Interestingly it turns out that the GMS might be useful for sound design as well as a composition and performance tool.