Digital concertina in Instrument Construction & Repair Posted August 9 · Edited August 9 by eskin Added details about Wakker and apps Yes, the device gyroscope is used to track the tilting on my iPad apps. You can calibrate the center point as well as set the amount of tilt required to trigger a direction change. There are two versions of this app, one is a standalone version that has my concertina samples built-in, the other is a MIDI controller that can be used to send MIDI messages to other apps. I think it's absolute fantastic that there is a lot of activity on building MIDI concertina controllers. I played a Wakker MIDI Anglo for a couple of years, an absolutely fantastic wireless instrument, but had some issues with the switching system. It had one wire of each button switch as the brass button lever, and the other as an L-shaped post next to the lever that would make contact when the button was pressed. The problem I experienced was that over time, since only the post was gold plated, corrosion would build up on the lever and you'd get switch bounce. The solution was to open up the instrument every few weeks (if you didn't play it every day) and clean all the levers with a pencil eraser. That was fine, but the instrument was built with standard machine screws going directly into the wood to hold the sides on. Repeatedly opening and closing the instrument eventually would risk strip out the screw holes in the wood. I think the same design with either magnetic switches and a more robust side attachment system that made it easier to maintain, perhaps with threaded insets instead of the screws going directly into the wood would have been the ultimate MIDI Anglo concertina. I really enjoyed it while I had it, it was fast, very responsive, and the wireless range was impressive. I ended up trading it for my late 18th century Lachenal Bb/F (it is the basis for the background image in the iPad app) to a guy who needed a silent instrument he could play in headphones because his dogs went absolutely crazy every time he practiced.