New England Patriots tight end Rob ‘Gronk’ Gronkowski joined Paul McCartney on stage in Boston on Sunday to help the legendary musician jam out to an old Beatles classic. A casually dressed Gronkowski strummed an invisible guitar as the two sang Helter Skelter during McCartney’s tour stop at Fenway Park, ESPN reports. McCartney posted a photo of the performance by the unlikely duo on Instagram, with the caption: “Gronk N’ Roll.” Gronk ripping it up with @PaulMcCartney @fenwaypark!