In the long tradition of trios that rock with efficiency, Band of Skulls were an excellent hard rock addition to this year’s festival. Patiently hammering out riffs and complementing them with male and female vocals, the group brought about the usually indie-centric crowd. Prompting chants of “Yeah” one on song and sang with fire and spirit “Cold flame / in my brain / it’s okay / ’cause I know it’s the best of me,” on another.