I’d like to see the ø more frequently, but I suppose der majestik møøse is not really all that metal. 
Møøsefärt would be pretty heavy.
I’m not sure, but Lars Ümlaüt was one of the avatar characters in the Guitar Hero videogame series.
I only know Deathmøle, which is sort of a fictional band become real.
NB though, ø is the same sound as ö, but the latter is less cool, sorry Swedes and Icelanders.
According to the episode of Cash Cab I saw last night, they’re so ubiquitous they’re called “rock dots.” Never heard that, myself.
It’s part of my name, so of COURSE it’s awesome.
Reminds me of a Tshirt I made myself once for an imaginary metal band: “Melödramatic Nöun Phrase.”
(Mind you, møøse bites can be nastei.) (50 points to anyone who gets that.)
And then there’s Sigur Rós, who lavishly pepper their song titles with accents and non-Latin characters (such as “Glósóli” and “Viðrar vel til loftárása”) just to make themselves sound exotic and eclectic.
(yes, that’s whoosh)
Pound for pound, Turkish and Finnish out-umlaut all the Germanic languages. I’m just sayin.
What looks even more metal to me are the Hungarian umlaut accents, though strangely no one’s ever exploited them. Hőw abőűt these?
Dibs on Ün̈n̈ëcëssäry Ümläüts as a band name!
I’m a little disappointed nobody’s mentioned Deathtöngue yet.
They’ve been known to use just one as well.
More importantly, zomg, somebody other than me knows of the best band nobody has ever heard of!!!