Now just note this is not an album. No. It's instead an aural mess.
The process is pretty straightforward. We take a song which was improvised at one point (the melody and the Dm to Em chords). Then we play it some more and somebody suggests the B section. Then somebody suggests the C section. Then somebody suggests new chord changes and we discuss where those chords should go (the last time we come back to the A section, as it turns out.)
Then we learn how we want to interact with one another. Then someone comes up with a descant -- an opposing line to the B section which works really well. And off we go to the races. Plus, somehow, I get to play blues guitar.
In practice this means, er, lots of practice. In this case, two hours playing two chords. I'm going to guess that we'll have done about 20 hours on this one song; working together in the studio. And the song will be about 20 minutes on an album.
That's not too bad actually. Especially if one is happy with the results.