The Love Story hitmaker has regularly invited celebrities on to the stage, with most recent surprises including Alanis Morissette, Matt LeBlanc and Ellen DeGeneres, and she continued to keep up expectations during her fourth night at the Staples Center in Los Angeles.

She brought rocker Beck on to perform his track Dreams with St. Vincent, real name Annie Clark, who also played guitar. Swift shared footage of their moment on social media and wrote, "Getting to play 'Dreams' with @Beck and @st_vincent is something I'll remember forever. I can't even express it."

She later duetted with John Legend on his hit single All of Me, and wrote online afterwards, "I heard @johnlegend and Chrissy were on the way to the show & called and asked if John felt like playing 'All of Me'."

Swift's five-date residency at the Staples Center ends on Wednesday night (26Aug15).