plugdata: Drawing Sound

For about six months I’ve been working with the plugdata graphical audio programming project to help develop the language for not only my personal sonic experimentation, but also to come to understand it well enough that I can use it as a tool for all sorts of digital experimentation and exploration.

This video is a … do we call this kind of thing an “instrument”? It has its own opinions about what it should sound like from moment to moment… and yet, you can collaborate with it. It’s not intelligent, but it makes patterns that you can somehow understand.

This harmonic drone is doing a few things at once:

  • It takes a MIDI note in and sets the fundamental to the corresponding frequency. So if you hit the A below middle C, it will set it to 440Hz. That note can come from an external keyboard or other controller, or you can click a key on the screen. The keyboard is set to pretty low notes so the upper harmonics don’t get painful.
  • It multiplies that frequency by a ratio that you select with the big horizontal slider, then multiplies it two more times. This is the core of additive synthesis. In principle, you can make any signal in the universe out of the correct sequence of sine waves, but in this case we’re making just four waves and laying them over each other, then adding additional harmonics to each one.
  • The VCO (“voltage controlled oscillator”) object is the one with the little cartesian plane crosshairs in it. The position of the dot on the plane is controlled by two LFOs (“low frequency oscillators”) inching along a sine wave at fractions of a wavelength each second. You can see the slow Lissajous patterns that results on those cartesian planes. That plane controls how much the oscillator puts out a sine wave (the smooth sound of, say, a flute); a sawtooth (more like the sound of a trumpet), a triangle (line a sine wave but slightly whinier), or a pulse wave (a simple up/down with sudden changes of states) , but which varies the amount of time that it’s up versus down even as it plays at a particular constant frequency.
  • LFOs also control the width of the pulse wave, which influences the timbre of the VCOs’ outputs separately from which wave shape or frequency it’s playing.
  • A four-channel mixer allows you to adjust how loud each of the harmonic oscillators are. In nature (generally), the higher the pitch of a harmonic, the lower its amplitude, so it sounds more “natural” when the higher frequencies are turned at least a little lower than the lower ones. The higher you’re playing a note on the keyboard, the more you’ll have to turn down the high frequencies for it to sound like “the same sound”.
  • The oscillators’s outputs are sent to an oscilloscope that crosses the fundamental with the other three oscillators harmonics so you can see the shape of the harmonics against the fundamental.
  • It then goes to the Digital/Analog converter in your phone or computer (with a volume control), which them amplifies the signal to move the air so you can hear the resulting wave.
  • Then it backs me up on my creative process on my Patreon page.

This type of patch is called “generative” because it generates patterns by itself whether or not you give it input. I’m trying to find a place for cyborg instruments, though, where you play with it, letting it show you forks in the road that you can choose to follow, while the patch responds to the musician’s footsteps as they follow that path. I don’t feel like this patch succeeds that well in meeting that objective, but it’s facing the right direction and headed somewhere really good.

You should download plugdata and play with it if you have any interest in how sound works. If you have curiosity but “are bad at programming” or “are bad at math”, then you should definitely download it and play with it. It’s still developing (very fast), but I have a pronounced interest in coming to understand ways that we’ve all been disinclined from the beauty of math, logic, and art, and the project will benefit from the perspectives of people who don’t already love making Computer Music in their computer science departments.

Because it’s developing so quickly, the best way to get ahold of plugdata is to download today’s build from the Actions page of the Github (which is really too bad. Github is not a good distribution tool). Your use and feedback now will influence how we develop it toward your interests and needs in the future.

If you’re interested in downloading the patch to play with (or getting help on downloading and experimenting with plugdata), join me on the xenophilia Discord with the xenophiliacs who support my art, games, and music by backing me up on Patreon, which will hook you up to the Discord automatically!

Modular systems are a function of industrial society. But do people of The Fifth World still know how to agree to standards? With their acute interest in efficiency, I think they might have carried that lesson forward!

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