Replace paper hymnals in places of worship with ebook readers (e.g. Kindles). Easy to update, zoomable display for the visually impaired...

And you could build in an app that tells you when you're off key.
-- smendler, Apr 09 2013

Maybe throw in an auto-tune pitch corrector.
-- RayfordSteele, Apr 09 2013



random, halfbakery