Electronic drum machines have been around for decades, and in the ’80s the Roland TR-808 in particular had a huge impact on modern music. The TR-808, like most drum machines since, lets musicians compose beats by selecting a tempo and what drum sounds to play on particular beats. It’s perfect for simple repeating beats that work well for everything from rap to pop. This Teensy-powered drum machine, on the other hand, uses a much more novel Euclidean rhythm.
The formal concept of Euclidean rhythm is fairly new, and was discovered by Godfried Toussaint in 2004. Despite being newly “discovered,” Euclidean rhythms can be used to create beats for just about any style of music you can think of. It works by taking the number of steps, and then dividing that by the number of hits. So, if you wanted 4/4 time with a bass drum kick every measure, you would set it to four steps and one hit. But, Euclidean rhythms get far more complicated when numbers aren’t evenly divisible and when they’re layered.
Morton Kopf wanted to experiment with Euclidean rhythms, and used a Teensy 3.5 to build their own Euclidean sequencer four channel drum machine. The interface is made up of four RGB rotary encoders from SparkFun surrounded by four 16 LED Adafruit NeoPixel rings. The musician can use those, along with four buttons and a small LCD readout, to select and divide beats. As Kopf demonstrates in the video, the beats start out pretty simple. But, by turning the dials, the math driving the Euclidean rhythm gets more complicated and results in more sophisticated beats.