So your a musician you've got you guitar and you can quite quickly write up a score sheet.
so you pop your score down like you would a midi file. Place in your song words put a few pointers down where you want your emotional shifts and pick your emotion for that bit of the singing.
Then when done the AI highlights different parts of the music and offers you suggestions until you have your pre-tune knocked out in 20 minutes. Studio quality with you singing well in it coming in an extended midi format.
This new .emidi file includes extra instrument data modules and extra voice data modules.
You can also export parts easily to a more advanced music making system when your ready to get started.
You guessed it, it actually sounds like you made it in a studio with you singing and playing the guitar well with a few other instruments and fx's. However after a year the novelty of it sounding like a real tune will ware off then it'll mainly just be useful to replace the midi file and give musical artists a kinda early studio view so they know mainly if they are going wrong with any of there thinking. even if it had rihanna's voice it would not sing like rihanna does on a tune it would sound more like rihanna singing but to some same formula as everyone else where extra character and vocal choices would be missing and people would notice this and mostly prefer a real studio versions especially after the novelty wares off.