Sam Smith has officially kicked off his world tour. Here, he celebrates the release of his debut album In The Lonely Hour with a live set at the Roundhouse in Camden, London where he performs songs off the album with three back-up singers and a dope string quartet. Jessie Ware also joins him on stage for a collaborative performance of 'Leave Your Lover'. Sam Smith's album In The Lonely Hour hits stores June 17th in the US. Check out the full video of his set in London above.