This was not an expected move! After 25 years in the band, guitarist Brent Hinds is out of the band in what is stated as a mutual parting.
As the post says touring will still go on as planned. This is a huge bummer as Brent has contributed some of the most memorable Mastodon moments. Mastodon and Coheed and Cambria will be in Green Bay on June 7th and we should know who their next guitarist will be by then.
