Kirk Windstein (Down, Crowbar), and Jamey Jasta (Hatebreed) are good friends and admirers of each other’s music. The two metal musicians have recently teamed up for Behind the Blackest Tears, the new album from their side project, Kingdom of Sorrow.

As the name suggests, the album features dark, melancholy lyrics and crushing, syrupy mid-tempo guitar riffs. Windstein’s Black Sabbath-inspired blues riffs, bent notes, aggressive bass lines and groovy lead guitar contrast Jasta’s har...