Basic / beginner production question

[3162Crew]

I have someone who has a guitar- and vocal tune recorded on his iPhone with no equipment or even a mic, who is a Covid doctor with absolutely no spare time. Wants me to produce a song (like an angry protest song) in a raw singer-songwriter feel. What would your approach be? Would I need to redo the vocals and guitar myself? Can you slot the vocal/guitar track into a DAW and just try to optimize it, maybe fix timing and add drums? Or maybe send stems to him, so he can listen on earphones and just do the vocals?

[CarlParadise]

In a quiet room, a phone recording can make a nice demo, call it v0 for version 0.

I have used a lot of voice/guitar and voice/piano phone demos by putting them in my Logic DAW. I figure out the approximate tempo, then copy/paste/stretch things to put roughly on the grid. Then I add bass, drums, or whatever to make my simple v1 demo. It still can have the vibe/energy of the original.

This can be used to figure out if you have the right tempo, groove, and key.