Taylor Swift is pulling out all the stops on her Eras Tour!Taking the stage in Las Vegas, Nevada Saturday, Swift treated the sold-out crowd at Allegiant Stadium to a special surprise from Marcus Mumford. The «Anti-Hero» singer was joined on stage by the Mumford & Sons singer for a special performance of «Cowboy Like Me,» off Swift's 2020 release, e.Explaining the origin for e to her fans, Swift revealed that it was Mumford who lent his home studio to her during the COVID-19 pandemic, to help her record the sister album to folklore.«I could not find a studio, essentially, and so Aaron was like, 'OK, let me call around and see if there's anyone who's cool and nice and generous and might be willing to offer up their home studio — if you do the right amount of testing, you're totally locked down, you're fully quarantined,» Swift shared. «So I was like 'Please, I really hope somebody comes through.