Well, you guys know how certain people hate rules...
I would say that as long as it's a band/artist you know well (ie you're not just finding them on bandcamp or YT and playing one song) and let's say they need to have been making music publicly (whether signed, gigging locally or on YT/Soundcloud/Bandcamp) for, what, a year? Just to do away with bands only starting up that your friend's girlfriend's brother's sister gave you a recording of. How does that sound? I'm sure there are lots of you who have been following for years the music of bands or singers most of us might not even know. That's the kind of thing I'm looking at.
Whatever everyone's comfortable with.
You know what? **** it: I'm hardly one with eclectic music tastes, but I doubt any of you have heard these guys, so let me have at least one shot at the table.
The Stars of Heaven - Irish Country/Rock band (defunct)
Active from 1983-1990
Anyone know them? Heard of them?