A new iOS App, Pen2Bow, is a Violin Bow MIDI Controller using the Apple Pencil on the iPad. Designer Dimos Gaidatzis' aim was to create a device for controlling bow movement for strings that is as intuitive as a breath controller. This is what he has to say about it...
Pen2Bow takes full advantage of the sensors in the Apple Pencil and generates 4 continuous MIDI controllers: velocity, force, tilt and orientation. These can be assigned for example to expression, vibrato, bow pressure and position on the bridge to drive a virtual violin - or to any other parameter to drive synthesizers.
But the key innovation is that it recognizes linear as well as circular pencil motion to generate bow movement from the user input. Circular motion enables the infinite extension of the bow that otherwise would be limited in length. This frees the user from constantly thinking about performing bow changes in order to prevent the bow from running out when the pencil reaches the edge of the iPad's surface. I believe it is one of the very few, if not the only practical MIDI input device for bowed instruments.
The software is optimized for minimal latency which amounts to about 10ms on the iPad Pro 10.5-inch and 12.9-inch(2.gen) and 20ms on the iPad Pro 9.7-inch and 12.9-inch(1.gen). Pen2Bow fully utilizes the high resolution positional information at 240Hz provided by the Apple Pencil to estimate robust bow velocities.
Pricing and Availability:
$7.99. Pen2Bow can be purchased on the Apple App Store.