Beat Mangler X is an automatic splice and stutter instrument that generates variations of a looped sample. This instrument is a descendant of the beat mangler Jean-Luc and I designed back in 2007. We’ve created several versions since, with today’s example having a reduced set of features compared to its ancestors. It supports random splicing, stereo stuttering and splice enveloping. The randomness of the instrument is controlled in the score; The user sets the odds that a random splice or stutter will occur. Though it shares many qualities of the built-in opcodes bbcutm and bbcuts, it definitely has its own personality. Since it is also coded in Csound, the internals of the instrument are exposed, and can easily be modified. For example, adding random pitch control.

There are two main principles used to drive the mangler. 1) Using a phasor to read through a stored loop in memory. 2) Using random for musical purposes. These will be covered this week as we continue with more synthesizer fundamentals tutorials.

Download beat_mangler_x.csd here.

For the source material of the audio example, we used the infamous Amen Break, “a brief drum solo performed in 1969 by Gregory Cylvester “G. C.” Coleman in the song “Amen, Brother” performed by the 1960s funk and soul outfit The Winstons.” You can acquire the loop in Step 1 of the Audio Tuts article Make a Crazy Drum and Bass Breakbeat by Slicing and Dicing in FL Studio. The loop itself has a fascinating history, which the following video makes apparent:

[youtube]http://www.youtube.com/watch?v=5SaFTm2bcac&feature=player_embedded [/youtube]

If you want to play with the instrument, which I highly recommend, try modifying the csd file in the following ways and see how far you can get: Load in a different loop, change the tempo, and play with the various p-fields. And of course, ask questions if you have any.

Synthesis Fall 2010

Much like the envelope, the low frequency oscillator (LFO) is a synthesis fundamental utilized for changing sound parameters over time. A LFO is basically the same thing as an audio oscillator, with the biggest difference is that they’re designed to run at a much smaller frequency range. The range is generally below the limits of human hearing, 0Hz to 20Hz. Though many analog and digital LFOs usually oscillate at higher frequencies. There are generally no restrictions for using an audio oscillator as an LFO.

Today’s example uses an LFO to modulate the frequency of a square wave oscillator. I use three different waveforms (triangle, sawtooth, square) so that you can hear how their shapes affect the sound. For example, at the lower frequencies, the triangle wave causes the pitch of the audio to smoothly go up and down while the square produces a trill-like quality.

In the listening example, you’ll hear everything from vibrato, to trills, to classic sci-fi lasers to something straight out of Pac-Man.

Download low_frequency_oscillator.csd here.

Synthesis Fall 2010