Imagine you’re listening to a live performance which includes a drum machine. Though the percussion is generally a nice addition, if the musician doesn’t change things up once in a while it can get static, or perhaps even a bit annoying. In order to introduce a bit of spontaneity into the beat, DrumKid is is an aleatoric drum machine by musical hacker Matt Bradshaw that offers “a variety of controls to alter a drumbeat live, using randomly generated drum hits which augment the original beat.”
In other words, each performance will be different, restoring some of the reason to actually see someone play live. Extra effect settings are available, including changing the pitch of the samples, reverse, bit crush, chop to make the beats more staccato, and control over just how random the computer generated beats are. Audio output is via a 3.5mm jack, and there’s a series of LEDs to indicate the progression of the drum sequence.
The DrumKid was programmed on an Arduino Uno and set up on a breadboard with potentiometers, buttons, and LEDs. The final version employs a similar configuration on a PCB, including the same ATmega328 as the Uno. Cleverly, the PCB forms part of the device’s minimalist case, with user inputs on the top and components on the bottom. It will be for sale in late 2019, but it’s open source with files available on GitHub, so you’re welcome to build one yourself!