Look into midi keyboard support

[TerryCavanagh]

In the past this wasn't supported through Adobe AIR, but it may now work with later versions. Alternatively, if a haxe port eventually happens, it should definitely be possible.

[ttofis]

I think SiON has that built in. If you check the source code it has something about midi. Maybe its just a matter of updating SiON and you will be able to do this.