The semi-annual Rokkjötnar festival has had a tough time of 2015. Earlier in the year, the festival booked a line-up of badass bands and announced a much-talked-about show for September 5. Unfortunately, they had to cancel the whole shebang when headliners Mastodon pulled out due to a pressing family matter. Rejoice, rockers! After a little bit of reshuffling, the festival is on once again, with Mastodon back on the bill and ready to rock alongside formidable Icelandic metalheads like Vintage Carvan, Kontinuum, Muck, Sólstafir, and more. Go ahead, buy your ticket and start practicing your air guitar now.