H-Pi Instruments is now shippping the TBX1 – a MIDI box designed to make custom keyboard tunings as easy as pushing a button.
Attach this little box to a compatible synth and you can make every key play any pitch you want. It comes preloaded with 128 tunings for you to try out, and it stores tuning tables in 4 layers, totaling over 500 tunings, which you can edit using the free TBXE Tuning Box Editor cross-platform software.
Set up your own tuning, upload it to the Tuning Box and plug it into any General MIDI controller and synthesizer to make your music.
In the above demo, the H-Pi Instruments Tuning Box TBX1 ($299), is used to retune a Yamaha PSR-310 ($149) on the fly.
This looks like it could be great for people interested in using alternate tunings.