Musical Hacks

1401 Articles

A device that reads sheet music and outputs MIDI

Sheet Music To MIDI Converter

December 22, 2014 by 11 Comments

Learning to read sheet music is a challenge for new musicians, so a group of Cornell students decided to make a robot do it instead. For their final project, they built a robotic sheet music reader (link warning: this page seems to automatically start a .mov file download when loaded).

As an input, the robot takes a piano roll. This is a long strip of paper with music printed on it, which can easily be fed through the reader. A rotational servo keeps the strip feeding at a constant speed, and passes it through the reader.

The reader is based on a Melexis MLX75306 linear optical array. This IC is a 142 x 1 array of photodiodes, which is designed for fuel quality sensing in cars. In this project, it’s been repurposed as a camera to read the music as it passes by. An array of LEDs illuminates the piano roll, providing a more accurate reading.

The components are connected to an Atmel ATmega1284P, which does all the required control and processing. It creates a MIDI output of the piano roll, which can be connected to any hardware or software synthesizer.

Beating The Skins Of Oatmeal Tins

December 21, 2014 by 3 Comments

Ithaca-based power trio [Nick, Roshun, and Ian] share a love of music and beating on things with drum sticks. To that end (and for class credit), they built a Digitally-Recordable, User-Modifiable Sound Emitting Tool (DRUMSET) using force-sensing resistors housed in oatmeal cans.

Anyone who has dealt with FSRs knows how persnickety they can be. In order to direct the force and avoid false positives, these enterprising beat purveyors suspended a sawed-off 2-liter bottle to the underside of each lid. This directs the force coming in from their patent-pending foam-enhanced drum sticks to the small, round sensing area of the FSR. There’s just enough space between the cap and the FSR to account for the play in the oatmeal can lid drum head when struck.

DRUMSET offers different-sounding kits at the push of a momentary switch. At present, there are four pre-programmed kits: the acoustic and electronic foursomes you’d expect, and a kit of miscellaneous sounds like hand claps and wooden claves that sound like something They Might Be Giants would have used on their first album. The fourth is called ‘Smoke on Water’, and is exactly what it sounds like. Should you tire of these, DRUMSET has a program mode with around 20 samples. These can be cycled through on the LCD and assigned to any of the four drums.

The microphone is for record mode, and whatever is recorded can be mapped to any drum. The memory limitations of the ‘1284P make for a 0.2 second sample of whatever is barked into the mic, but that’s plenty of time for shouting ‘hack!’ or firing off whatever hilarious bodily sound one can muster. We think this four track-like functionality of DRUMSET has interesting recording and live performance implications. The team’s future plans include space for longer samples and more robust drum construction (although it is possible to do this without any drums whatsoever). They’d also like to add more drums in case Neil Peart calls. The beat goes on after the break.

Continue reading “Beating The Skins Of Oatmeal Tins” →

One Man’s Mini Symphony Of Many Strings

December 20, 2014 by 23 Comments

If you don’t get along with your orchestra, screw ‘em. [Vladimir Pliassov] proves that you can play each of the virtuosic string instruments yourself, all at the same time (with the exception of the double bass of course).

For the life of me, I can’t imagine how long it took to get situated in this spider’s web of moving parts, but it’s impressive. With the help of this unique mechanical invention all his own, [Vladimir] is able to finger not only the neck of a violin and viola, but also a cello hoisted at an angle below his desk so that he can execute chords with his FEET. To help with the actual sound-making, a complex series of resinous fibers turn on a continuous mill of wooden beams and are tensioned ever so carefully over the bridge of each instrument. [Vladimir] controls which string is making contact with the turning fibers with a pulley wrapped around his thigh that rocks the body of the instrument back and forth.

[Vladimir] gives us an overview of his machine and how it works in the video below. If you’re itching to see it used for the purpose it was created for, well… there’s a video for that too. Even though the quality of the performance suffers a little due to the complicated nature of the setup, [Vladimir] is playing of all things, a piece for the pipe organ by J.S. Bach. Bach being hard mode in any case, let alone the one where you’re playing all the instruments yourself.

Thanks [tinkartank] for pointing out this unique invention. It’s definitely worthy of some awe!

Continue reading “One Man’s Mini Symphony Of Many Strings” →

Tiptoe Through The Tulips In No Time With Ukule-LED

December 17, 2014 by 8 Comments

Take it from someone who has played at the guitar for over 20 years: reading sheet music can be a big stumbling block to musical enjoyment. Playing by ear is somewhat unreliable, tablature only works well if you’re already familiar with the tune and tempo, and pulling melody from chord charts is like weaving fiction from the dictionary. A lot can be said for knowing basic chord formations, but it can be difficult get your fingers to mimic what you see on the page, the screen, or someone else’s fretboard. Enter Ukule-LED, a learning tool and all-around cool project by [Raghav and Jeff] at Cornell.

Ukule-LED uses 16 NeoPixels across the first four positions of the fretboard to teach chord positions. All 16 NeoPixels are connected in series to a single pin on an ATMega1284P, which sits on a board mounted to the bottom of the uke along with power and serial. [Raghav and Jeff] set the NeoPixels below the surface so as not to interrupt playability. The uke can operate in either of two modes, ‘play’, and ‘practice’. In ‘play’ mode, the user feeds it a text file representing a song’s chords, tempo, and time signature. The LEDs show the chord changes in real-time, like a karaoke teleprompter for fingers. In ‘practice’ mode, the user enters a chord through the CLI, and the lights hold steady until they get a new assignment. Knowing which fingers to use where is up to the user.

To add another layer of learning, major chords alight in green, minor chords in red, and 7th chords in blue. These are the currently supported chord types, but the project was built with open, highly extendable Python sorcery available for download and subsequent tinkering. Go on tour after the break.

Continue reading “Tiptoe Through The Tulips In No Time With Ukule-LED” →

Meet Registroid – Mutant Cash Register Music Sequencer

December 15, 2014 by 5 Comments

73 years ago WWII was in full swing, the world’s first computer had not yet crunched atomic bomb physics and department store cash registers had to add up your purchases mechanically. Back then, each pull caused the device to whirl and kerchunk like a slot machine. [David] & [Scott] kidnapped one of those clunkers and forced it to sing a new tune. Thus the Registroid was born, a self-described “mutant vintage cash register that is a playable, interactive electro-house looping machine.” Why did no one else think of this yet?

Inside, the adding gears and tumbling counters were gutted to make room for the electronics, amp and speaker. Keys were converted to Arduino inputs that then feed to MAX/MSP which serves as a basic midi controller. On top, five “antennae” lamps with LEDs serve as a color organ where they pulse with the audio as split up by an MSGEQ7 equalizer chip. Each row of latching keys corresponds to a different instrument: drum beats, baselines, synths, and one-shots.

We have seen similar things done to a Game Boy and typewriter before, but a cash machine is new to us. Perhaps someday someone will flip the trend and type their twitter messages from an antique harpsichord.

The Registroid appears quite popular when on display at local events, including some wonder when a secret code opens the cash drawer.

Continue reading “Meet Registroid – Mutant Cash Register Music Sequencer” →

Sqonkbox 55 Is A Cigar Box Organ Of Awesome

December 14, 2014 by 10 Comments

Sometimes, the best birthday presents are the ones you give yourself. In [Dino]’s case, they’re the ones you make for yourself.  In honor of his 55th, he built the Sqonkbox 55, a 13-note cigar box organ based on a 555 and amplified with an LM386.

It’s based on a 555 wired in astable mode, turning it into an oscillator that outputs a frequency. This frequency is determined by the resistors between pins 6 and 7, another between 7 and 8, and the capacitor between pin 2 and ground. [Dino] shows a breadboard version first, with a single tuning pot and momentary acting as a piano key. As he explains, this portion of the circuit is repeated 13 times with pots and momentaries that he arranges like piano keys through the lid of a cigar box.

“Sqonkbox,” you ask? A second 555 in astable mode sends the output through an LED. This LED stands face to face with an LDR, and they are shrouded in this configuration with black heat shrink tubing. The ‘sqonk’ 555 changes the frequency of the first 555, providing a clippy, rhythmic tone at the rate set by a potentiometer. [Dino]’s full video of the build is after the break. A BOM is forthcoming, but it’s easy enough to puzzle it out between the video and the lovely, Forrest Mims-esque schematic.  Continue reading “Sqonkbox 55 Is A Cigar Box Organ Of Awesome” →

laser keyboard

MIDI Keyboard With Frickin’ Laser Keys

December 13, 2014 by 10 Comments

MIDI instruments are cool, but they’re not laser cool. That is, unless you’ve added lasers to your MIDI instrument like [Lasse].

[Lasse] started out with an old MIDI keyboard. The plan was to recycle an older keyboard rather than have to purchase something new. In this case, the team used an ESi Keycontrol 49. They keyboard was torn apart to get to the creamy center circuit boards. [Lasse] says that most MIDI keyboards come withe a MIDI controller board and the actual key control board.

Once the key controller board was identified, [Lasse] needed to figure out how to actually trigger the keys without the physical keyboard in place. He did this by shorting out different pads while the keyboard was hooked up to the computer. If he hit the correct pads, a note would play. Simple, but effective.

The housing for the project is made out of wood. Holes were drilled in one piece to mount 12 laser diodes. That number is not arbitrary. Those familiar with music theory will know that there are 12 notes in an octave. The lasers were powered via the 5V source from USB. The lasers were then aimed at another piece of wood.

Holes were drilled in this second piece wherever the lasers hit. Simple photo resistors were mounted here. The only other components needed for each laser sensor were a resistor and a transistor. This simple discreet circuit is enough to simulate a key press when the laser beam is broken. No programming or microcontrollers required. Check out the demonstration video below to see how it works. Continue reading “MIDI Keyboard With Frickin’ Laser Keys” →