Hi Don, you may or may not know of the many great Ipad ios music apps out there.(Others may not either, I don't know)
And I'm not just talking lyric/pdf apps. Check out some of these great synth apps. Morphwiz and samplewiz, made with Jorden Rudess's (of Dream Theater fame) input.
I personally love the Magellan synth to the point of buying an M-Audio midi keyboard controller to use with it. Check it out on Youtube. For a measley few bucks an awesome synth to use on your tablet. there are more tutorials for Magellan. It is a very deep synth app with numerous great features. Research.