I'm seeking an informed app recommendation. Basically I'm looking for something to produce good-sounding realizations of original compositions (especially orchestral music). I could see this going one of two ways - either playing directly into the app with something like the iRig Keys, and recording the different voices playing their different parts, or importing a .midi or other file type from composition software on my PC and assigning voices to the various parts. Does anyone have any recommendations for an app that would suit either of these needs? Is this something I should be doing with Garage Band or Thumb Jam, perhaps? Any comments about the sound quality of voices, as well as the overall accessibility of recommended apps, would be appreciated. Thanks!