Last week myself, a rapper, and a singer went to a friends place who has a studio in his home. The home / studio owner is also a bass player. We started off with no plans at all but ended up almost recording a whole track. As usual it just started off with a chord progression. I believe it was the key of Gminor. That chord progression was extended to make room for separate chorus and verse parts.
The below video was taken by me recording everyone listening and miming over what we had pre-recorded.