This video, via Jason Hotchkiss, demos Le Strum – a MIDI Strummed Chord Controller Kit, a sort of bizarre love child of an Omnichord & a Stylophone.

Using combinations of buttons, you can select a chord type (maj, min, 7, maj7, min7, dim, aug) and root note. The chord is then mapped across the pads, which you play with a wired stylus, sending output by MIDI.

Le Strum does not generate sounds itself, so it needs to be used with a MIDI instrument. 

Specifications:

• Kit contains PCB and all components and hardware required to build LE STRUM
• Soldering is needed to assemble the kit
• A PP3 battery is required (not included)
• Integrated ON/OFF switch and power LED
• 4mm banana plug stylus with keepy-hole in PCB
• Designed for hackability (e.g. solder wires to the provided holes on the pads to make proper “strings” to pluck)
• Transmits on MIDI Channel 1 for stylus activity and MIDI Channel 2 for Chord Buttons.
• Output is to a standard MIDI 5-pin DIN socket.
• Size 98mm x 75mm x 45mm (incl MIDI socket)
• Weight approx 120g with battery
• OPEN SOURCE hardware design
• OPEN SOURCE firmware for PIC16F1825 microcontroller.
• Firmware source code (SourceBoost C) and compiled HEX images available on GitHub (A PICKit2 or equivalent programmer is required if you want to load alternative or updated firmware on to the chip)

Le Strum is available as a kit for US $45.