I’ve received several questions about the TickRate UGen that I’ve used in some recent Sound Bytes. Quite simply, this is a UGen that allows you specify an audio generation rate. Setting a rate of 1 means that the UGen patched to TickRate will be ticked every time that TickRate is. Setting a rate of 0.5 means that the UGen patched to TickRate will be ticked at half the rate of TickRate (every other sample). Setting a rate of 2 means that the UGen patched to TickRate will be ticked twice every time that TickRate is ticked. The sample frame that TickRate generates can either be the same as the most recently generated sample frame from the UGen patched to it, or you can have it interpolate between that sample frame and the next sample frame from the UGen patched to it. At low tick rates, non-interpolated audio will sound like it is being bit-crushed. Essentially, this UGen allows you to control the sample rate of any UGen patched to it, with the limitation that you won’t be able to patch the output of that UGen anywhere else. That limitation is not enforced, but if you do so, your audio will not sound correct.
As for where to get the TickRate UGen, you can either copy the file from the Minim GitHub repo, or you can pull the repo and build the library locally.
I’ve been working on this one for a few days. It follows the same principle as the beat generator from my previous post: whether or not a note is added to the generated sequence at a given step is determined by a probability. However, unlike the beat generator, this one doesn’t sequence distinct sounds. Instead, it is essentially generating timed control changes for effects on two sound files that are continually playing.
The first file is the vocal track from Half Life by Imogen Heap. Its playback rate is adjusted to the chosen tempo and “notes” in the sequence for it are turning on a sample-repeat effect. For each trigger of the effect, the length of the sampled audio is determined randomly based on the settings in the Vox Glitch range.
The second file is a loop from the beginning of Hydra Remix By Koen Groeneveld. The notes in the sequence for that track are setting loop points in a looping FilePlayer, though the resulting sound is the exact same kind of thing going on with the vocals. Once again, the length of the repeated audio is determined based on the settings in the Perc Glitch range. You can also specify whether you want each triggered glitch to fade in over its duration or not, which is kind of a nice effect.
Finally, you can choose to have a steady kick drum play underneath all the glitching to give yourself a good reference point. I’ve had a lot of fun playing with different settings, it’s like endless minimal, glitchy remixes of Imogen Heap. Try it out!
Probably the coolest Sound Byte yet, this one will generate drum beats based on probabilities for each sixteenth note in a measure. The sound-set is basic: kick, snare, hat, plus a chime loop that is overlaid for a little melodic flavor. You can tweak the probability of all the steps independently, or just click a button to set them all to new random values. Two “modes” allow you to specify whether you want the kick and snare to ever play at the same time and some simple rules are used to determine the amplitude of each note. I considered putting in panning of some kind, but decided it could go in a later iteration. I may do a bassline generator along the same lines at some point. Check it out!
I wrote a UGen the other day that allows you to change the tick rate (or sample rate, if you like), of any UGen that you patch to it. After making a mouse-driven example to test it out, I created this example so that the change in the tick rate could be driven by the audio itself. Here, the current loudness (RMS amplitude, to be exact) of the audio being looped directly adjusts the playback speed. Louder parts result in a higher tick rate. What you get sounds like a really broken record player. Not only is it stuck looping the same four bars, but it sounds like the timing belt is having all sorts of issues. Check it out!
I’ve been meaning to try out some digital Moog filter code. A digital Moog filter is simply a filter that attempts to model the analog filters found on Moog synthesizers. It’s got two knobs: frequency and resonance. I yanked some code from musicdsp.org, a wonderful resource, and wrote a really simple UGen with it. I meant to write more of a song, but there’s never enough time for that in these evening coding forays. So instead, you get this kind of avant-garde slow tuning thing using amplitude modulation and tweaking of the filter values. Have a listen!
Eventually, we plan to add a UGen to Minim that will allow you to control the generating speed of any other UGen, but that got me thinking about how you might do something similar with existing components. So, I struck upon the idea of using an Oscil as a looping sampler by using an audio file as the Waveform and setting the frequency of the Oscil to be very low. The fun thing about this is that if you set the Oscil to a negative frequency, the sound will play in reverse. Additionally, I thought it’d be fun to be able to automate the changing of the frequency by having an LFO control the frequency of each Oscil (left and right channels of the original audio file). So here’s a sketch that lets you play with this setup:
I’m picking my way through Real Sound Synthesis for Interactive Applications by Perry R. Cook (one of the authors of the STK) and decided to start making small apps to demonstrate the different kinds of synthesis he covers in the book. This first one let’s you set the variables of a mass-spring-damper system and then trigger it, which is exactly the same as setting the coefficients of a two-pole IIR filter and sending an impulse into it (as it turns out). Check it: