Lissie is an American singer/songwriter who mostly has Kid Cudi to thank for her fame. She first broke out in 2010 with her cover of his "Pursuit Of Happiness," and last night during her concert in Paris, brought out the man to help out on his own song.
Beginning with Cudder crouched to the side of the stage, the performance soon incorporates him, with Lissie backing up to allow him to sing lead vocals.
It's also worth noting that Lissie's studio version of "Pursuit Of Happiness" was sampled in Schoolboy Q and A$AP Rocky's "Hands On The Wheel." A cover of a hip-hop song being sampled to become an entirely new hip-hop song? Now that's meta.