It's not so much a dark comedy, more slapstick, coated with an absurd parody of death metal. The main character Soichi Negishi longs for success as an independant singer songwriter. But to pay the bills has found himself a member of the increasingly successful and KISS inspired death metal band, Detroit Metal City.Although I'm yet to see the anime, I'm a big fan of Kenichi Matsuyama as Negishi. And it's hilarious to see Gene Simmons with a little cameo.
The anime series was produced by Studio 4°C who are responsible for the recent Berserk remake, and have also worked on Batman, Halo, Street Fighter, Thundercats, and Transformers anime. The advantages of the anime series is that it can ramp up the more extreme elements with sequences that are just not possible with a live action version. And it doesn't disappoint.
The Detroit Metal City manga has just been made available digitally in Japan. So if you have a Sony Reader, or there is also the app for Android phones and tablets. Unfortunately it's not supported on my rather dated Galaxy S.
Check out the author of Detroit Metal City, Kiminori Wakasugi, on Twitter: https://twitter.com/wakasugi_k
And you can download the series from the Sony Reader Store here: http://ebookstore.sony.jp/index/comic/