Banks of the Boneyard 17.1.1

SIGMusic’s Giant Piano

Every fall ACM SIGs sit down and ponder what to do for their semester project. Is it going to be a fun, beginner friendly project? Or will it be a gruelling technically amazing project? Is it going to be a fun demo? Or will it be a poster presenting a technical report? Often times this thought process goes hand in hand with deciding how to contribute to EOH. This year, SIGMusic wanted to create a fun, interactive EOH demonstration in where attendees at EOH can easily see their input create something or do something. Ideas flew around for a couple of weeks until a consensus was reached: build a giant piano.

Grand Piano

The aptly titled Grand Piano was ambitious as there were significant hardware and software components and every interaction and piece had to be planned carefully. They wanted the piano to be accessible to people, robust to people using it and also something that implements a good amount of functionality without being ridiculously complex (Roli’s squishy, pressure-sensitive keyboard). The build process was divided into two parts: design and construction.

The design phase took place during the fall semester. The piano itself is an 157:1 scale and designed to be played with one’s feet. Each of the piano keys is placed on top of a force sensitive resistor whose state is monitored with an Arduino. This signal is then pushed through a MIDI port. The piano is wired to act as a MIDI controller/keyboard and sends standard signals which can be handled with MIDI APIs or MIDI compatible software.SIGMusic choose to write their own web visualizer using the Google Chrome MIDI API. The web app was capable of playing simple games which SIGMusic in the style of Guitar Hero and Space Invaders and implemented with timbre.js and PhysicsJS.

Wiring for keyboard

The building started in the spring. Parts were requested and ordered and it was a rush as build process wasn’t actually started until the week of EOH. There were many late nights in the rush to finish, and test began and ended just before the actual demo but they pulled it off. The 8 ft long foam keyboard implements a single complete octave and can be daisy changed to make a fuller piano. Combined with the software projected on the screen, attendees had a great time playing space invaders while making some sweet tunes.

The EOH Demo

The biggest challenge SIGMusic faced this EOH is the same thing many people face when presented with trying to come up with an ideas that solve broad goals, in this case being both fun and educational. It takes a lot of debate, discussion and prototyping to narrow down broad ideas to a clear project. The piano worked out as it is a non trivial project, so the members of SIGMusic learned a ton. However it was still a simple enough concept to boil down and explain to visitors, not to mention the ability to just let attendees play with the device. They also had to deal with many problems that face game designers when working on the software: deciding visuals style and gameplay mechanics. The choice of a space invaders/guitar hero style game with no lose condition allows users infinitely create music.

The Grand Piano was only one of ACM’s projects at EOH this year, and there is much more to talk about. If you want to check out the Grand Piano design and source code check out SIGMusic/Grand-Piano and SIGMusic/Grand-Piano-Server