NTH: Scrolling background

Would be nice to have a background that scrolls, or changes over time... e.g. a star field or something... even better if we can map it to a midi button/note (so that we can change it real-time using a device).

As a bonus, this same thing could include some special effects that can be mapped to specific keys on one of the inputs... e.g. "background flash", or "initiate smoke machine" ;)