In recent years we’ve seen a variety of new technologies that aim to offer a more expressive synth playing experience than you’d get with a traditional keyboard. From poly-aftertouch and MPE, to devices like Expressive-E’s Osmose and the multi-touch Morphé controllers found on Artura’s PolyBrutes – it’s fair to say expressivity is hot right now.
One avenue few designers have explored is the idea of ‘bowing’ a synth engine, in the manner you would stringed instruments like a violin or cello. DIY-minded Japanese musician Washiyama Giken has taken it upon themselves to address this with their homemade ‘Key-bowed’ instrument.
In an explanatory video – which you can watch above, turn on captions for translation – the creation of the Key-bowed is explained by its creator. At the heart of the instrument is an Arduino UNO A4 Minima board, running a physical modelling synth engine. This is built into one of Roland’s K-25m keyboards, which are mini key controllers designed to house Roland’s Boutique synths. The top panel construction and bowing sensor are homemade.
“The basic mechanism is to make sound by inputting the driving waveform picked up by a piezo sensor, attached to an acrylic plate into a string vibration model, implemented on an Arduino Uno R4 Minima,” Washiyama Giken explains in a blog post [via translation].
As a design it’s actually not as out-there as it might first appear. Physical modelling synths such as AAS Chromaphone or Baby Audio’s recent Atoms are effectively built on the same principles as a traditional stringed instrument, whereby an input – such as a pick or bow – is used to ‘excite’ the resonant elements of the instrument’s acoustic body. If anything, it’s surprising we haven’t seen more of this idea – using a traditional ‘exciter’ to trigger a virtual resonance – from synth designers before.
Naturally, given its DIY nature, don’t expect the Key-bowed to appear in your local music store any time soon. Here’s hoping synth designers are taking note though.
