Rob Gronkowski joins Paul McCartney on stage at Fenway Park

New England Patriots players report to training camp July 27, which leaves a bit more time for the "Summer of Gronk" to check a few more boxes off the "fun" list.

File this one under the category of "Gronk the Rocker."

In a surprise on Sunday night, Patriots tight end Rob Gronkowski joined Paul McCartney on stage during McCartney's concert at Fenway Park. The song that Gronkowski helped McCartney perform was "Helter Skelter."

"Look out helter skelter helter skelter

"Helter skelter

"Look out helter skelter

"She's coming down fast

"Yes she is

"Yes she is."

Gronkowski was dressed in blue shorts and a white collar shirt, and strummed an air guitar while dancing on stage and calling out "Helter Skelter!"