Last week, a good portion of the 2013 Scion Rock Fest lineup was revealed, with the Melvins on the top line along with a mystery co-headliner. Now it's been revealed that thrash metal icons Testament will co-headline the hard rock and metal-leaning event in  Memphis, Tenn.

The two bands will be joined on the bill by the previously announced Municipal Waste, Six Feet Under, Arsis, the Casualties, A Life Once Lost, Impaled, Vision of Disorder, Code Orange Kids, Pallbearer, Subrosa, Ice Dragon, the Shrine, Indian Handcrafts, Anciients, and Noisem.

New acts named for the June 1 music festival include Whitechapel, the Obsessed, Corrosion of Conformity, Negative Thunder, Vektor, Touche Amore, the Gates of Slumber, Hot Lunch, Rotting Out, Call of the Void, Gigan, Dirty Streets, Inter Arma and Complete Failure. See the full lineup poster below.

The event is free to the public, but an RSVP is required. Further details on how to obtain entry will be revealed on April 10.