[Attoparsec] has been building intriguing musical projects on his YouTube channel for a while and his latest is no exception. Dubbed simply as “Node Module”, it is a rack-mounted hardware-based Markov chain beat sequencer. Traditionally Markov chains are software state machines that transition between states with given probabilities, often learned from a training corpus. That same principle has been applied to hardware beat sequencing.
Each Node Module has a trigger input, four outputs each with a potentiometer, and a trigger out. [Attoparsec] has a wonderful explanation of all the different parts and theories that make up the module at the start of his video, but the basic operation is that a trigger input comes in and the potentiometers are read to determine the probabilities of each output. One is randomly selected and fired. As you can imagine, there are loops and even dead-end nodes and for some musical pieces there is a certain number of beats expected, so a clever reset signal can be sent to pull the chain back to the initial starting state at a regular interval. The results are interesting to listen to and even better to imagine all the possibilities.
It’s not every day we see a grand piano with a Raspberry Pi inside, let alone one with 96 motors, but sometimes we get lucky. The contraption in question is one developed by [Konstantin Leonenko], as part of a collaboration with composer [Patricia Alessandrini] for a piece she created inspired by Ada Lovelace. Specifically, [Patricia] was inspired by Ada’s idea that an “analytical machine” would, someday, be able to create music on its own. [Konstantin] and [Patricia] worked together to make a machine that would learn from it’s human co-performers and create music with them.
Their creation, rather than just one tricked-out keyboard, is actually a portable attachment that can be easily fitted to any grand piano. Each of the device’s 96 motors drives a plastic “finger” that excites the piano’s strings. The result is a sound unlike any other — and you really need to experience it so click through that link at the top for the demo video.
Rather cleverly, the fingers are designed such that their dynamics help to mask the sound of the motor (a must for performances) while simultaneously enhancing the string’s timbre. Like any project, this one went through a number of iterations over the two-year design process, and even spun off into an entirely new, glove-based version.
We’ve seen some awesome music tech hacks, and this one fits right in with the rest. It’s always exciting to see an instrument as ubiquitous as the piano be used in new and refreshing ways. Be sure to check out the link at the top for a video of this incredible instrument in action!
The build is based on a Raspberry Pi Zero, secreted away underneath a table with a USB RFID reader attached. Atop the table are a series of RFID cards upon which [hoveeman] printed the artwork from his favorite albums using a special caddy in an inkjet printer. Through some Python code and shell scripts, when scanning a card, the Pi Zero is able to trigger all the Google Home compatible devices in the house to play the album selected at the same time.
It’s a visually enjoyable way to cue up some music, and likely more reliable than most voice assistants, too. We can see this being particularly useful for Weezer fans; with the band’s many self-titled releases, Siri and the Google Assistant typically fail to play the right album on request. We’ve seen other beautiful RFID jukeboxes before, but one player that really sticks out ditched the RF and just uses computer vision with vinyl albums as the ID.
The art-music-technology collective “Electronicos Fantasticos!” (commonly known as Nicos) is the brain child of artist/musician [Ei Wada] in Japan. They revive old, retired and out-dated electrical appliances as new “electro-magnetic musical instruments” creating not just new ways to play music, but one that also involves the listener as a musician, gradually forming an interactive orchestra. They do this by creatively using the original functions of appliances like televisions and fans, hacking them in interesting ways to produce sound. The project started in the beginning of 2015, leading to the creation of a collaborative team — Nicos Orchest-Lab — around the end of that year. They have since appeared in concerts, including a performance at “Ars Electronica”, the world’s largest media arts festival in 2019.
For us hackers, the interesting bits can be found in the repository of their Work, describing sketchy but tantalising details of the musical instruments. Here are a few of the more interesting ones, but do check out their website for more amazing instruments and a lot of entertaining videos.
CRT-TV Gamelan – A percussion instrument made from old CRT monitors. Coloured stripes projected on the screen cause changes in static-electricity picked up by the players hands, which then propagates to an electrical coil attached to their foot. This signal is then patched to a guitar amplifier.
Electric Fan Harp – They take out the fan blade, and replace it with a “coded disk” containing punched holes. Then they shine a bulb from under the rotating disk, and the interrupted light is picked up by an optical receiver held by the player. Controlling the fan speed and the location of the receiver pickup, they can coax the fan to produce music – based on the idea “What if Jimi Hendrix, the god of electric guitars, played electric fans as instruments?”
Barcoder – This one is quite simple but produces amazing results, especially when you pair up with another Barcoder musician. The output of the barcode reader is pretty much directly converted to sound – just wave the wand over printed barcode sheets. And it works amazingly well when pointed at striped shirts too. Check out the very entertaining videos of this gizmo. This led to the creation of the Barcodress – a coded dress which creates an interactive music and dance performance.
The Striped Shirtsizer
Striped Shirtsizer – This one is a great hack and a synth with a twist. A camera picks up video signals, which is then fed to the “Audio” input of an amplifier directly. In the video on the project page, [Ei Wada] explains how he accidentally discovered this effect when he wrongly plugged the “yellow” video out connector to the audio input of his guitar amplifier. At an outdoor location, a bunch of people wearing striped shirts then become an interactive musician-audience performance.
The Kankisenthizer
Kankisenthizer a.k.a Exhaust Fancillator – This one consists of an array of industrial exhaust fans – although one could just as well use smaller instrument cooling fans. On one side is a bright light, and on the other a small solar cell. Light fluctuations picked up by the solar cell are then fed to the guitar amplifier. The array consists of fans with different numbers of blades. This, coupled with changing the fan speed, results in some amazing sound effects.
There’s a whole bunch more, and even though the “instructions” to replicate the instruments aren’t well documented, there’s enough for anyone who’s interested to start experimenting.
While the build does include some other favorites such as “Baby Shark” and would probably work with any song (or audio of sufficient volume) the build is still pretty interesting. It’s based on a 555 timer circuit which powered an ultrasonic sound gun, but was repurposed for this build. The ultrasonic modules were replaced with piezo modules which were waterproofed with silicone. The sound produced vibrates at a frequency which resonates with the mosquito larvae and is fatal to them. [Shane] put the build into a small boat which can be floated in any pond, bird bath, horse trough, or water feature.
The major caveat to this build is that it may be damaging to other beneficial animals such as fish or frogs, so he suggests limiting its use to uninhabited stagnant water. Either way, though, it’s a pretty unique way of taking care of a mosquito problem not unlike another build which takes care of these insects in water a slightly different way.
The band Kraftwerk hit the music scene with its unique electronic sound in the 70s in Germany, opening the door for the electronic music revolution of the following decade. If you’re not familiar with the band, they often had songs with a technology theme as well, and thanks to modern microcontroller technology it’s possible to replicate the Kraftwerk sound with microcontrollers as [Steven] aka [Marquis de Geek] demonstrates in his melodic build.
While the music is played on a Stylophone and a Korg synthesizer, it is fed through five separate Arduinos, four of which have various synths and looping samplers installed on them (and presumably represent each of the four members of Kraftwerk). Samplers like this allow pieces of music to be repeated continuously once recorded, which means that [Steven] can play entire songs on his own. The fifth Arduino functions as a controller, handling MIDI and pattern sequencing over I2C, and everything is finally channeled through a homemade mixer.
[Marquis] also dressed in Kraftwerk-appropriate attire for the video demonstration below, which really sells the tribute to the famous and groundbreaking band. While it’s a great build in its own right and is a great recreation of the Kraftwerk sound, we can think of one more way to really put this project over the top — a Kraftwerk-inspired LED tie.
From a guitar hacking point of view, the two major parts that are interesting to us are the pickups and the volume/tone control circuit that lets you adjust the sound while playing. Today, I’ll get into the latter part and take a close look at the components involved — potentiometers, switches, and a few other passive components — and show how they function, what alternative options we have, and how we can re-purpose them altogether.
In that sense, it’s time to heat up the soldering iron, get out the screwdriver, and take off that pick guard / open up that back cover and continue our quest for new electric guitar sounds. And if the thought of that sounds uncomfortable, skip the soldering iron and grab some alligator clips and a breadboard. It may not be the ideal environment, but it’ll work.
