It was an indie rock lover's delight on the late-night TV circuit last night. In addition to Cults performing on Late Night With Jimmy Fallon, we also watched as Los Campesinos lit up the stage of The Late Show With David Letterman. The Welsh seven-piece chose to run through emotionally heavy "By Your Hand," which appears on their latest album, Hello Sadness. As melancholy as some of the lyrics might be, these guys still have loads of energy. They also still know how to write endearingly catchy indie pop, an ability that likely caught the attention of plenty of Letterman viewers last night. Watch the performance below.