Gov’t Mule’s Mighty High Tour with Grace Potter & the Nocturnals opened on Wednesday night in Toronto. Last evening marked the first American date of the tour with a show at the House of Blues in Cleveland, OH. At the close of the first set, the Mule invited Potter to the stage for two songs from Crosby Stills Nash and Young’s Four Way Street recording. First up was a version of the Stephen Stills song ‘Find the Cost of Freedom.’ Then Nocturnals guitarist Scott Tournet also came out, joining in for a geographically-apt cover of Neil Young’s ‘Ohio.’ The two groups travel to Wallingford, CT this evening for a show at the Chevrolet Theatre.