Break Into Summer with Rock Music Featuring Primus and Mastodon The legendary rock group known as Primus has paired together with Mastodon to tour this summer across the United States. Primus recently released The Desaturating Seven on September 29, 2017. The band has been chopping at the bit to showcase their latest material to live audiences. This tour will be an excellent double shot of hard rock music for attendees. One of my favorite Primus stories was told to me by a friend years ago. He said he was watching them perform at Bonnaroo, and a mosh pit started to take place.