If you choose a name like "Butter" or "Poodle" or "Feldspar" or "Ampersand" or "Octothorpe" or "add", or some other English word or phrase that sounds cool and that somebody else might want to use for a band name-- that is a risk you take when choosing that name. Hell, even stuff like "Loyalty Day" or "Urine Luck" aren't completely safe from this phenomenon.
What -is- safe from this? "The Jon Benjamin Band"? "lsaidjaosidajosj"? It's less likely someone will coincidentally choose one of those band names out of the blue, but as soon as someone submits under any band name, anyone can use that name.
[paraphrase] ... first time in 5 years ... not going to worry about it ... [/paraphrase]
That doesn't mean there shouldn't be a concrete policy about this. What's going to happen with the artist archive? Will the "original" Feldspar have somebody else's songs on his page? You'll probably wind up having to distinguish between the two Feldspars somehow, so now might be a good time to set the policy.
Maybe the response to a duplicate name would be something like, "Sorry, that name's already taken, you'll have to be 'Feldspar (2)' or choose something else." ?
Just my $0.02...