Handclap-based songs have proliferated this past year or so, from hip-hop and R&B “clappers” to neo-folk hoedowns. Denmark’s Quadron put a jazz-soul twist on the affair last night on Late Show With Letterman. Robin Hannibal — the production half of Woman duo Rhye — and smoky-voiced singer Coco performed “Hey Love” from their just-released album Avalanche. As Coco clapped and swayed with the band, the rendition picked up a throwback elegance that culminated when she briefly let her red blazer fall from her shoulders like a jazz-age cabaret singer. While Letterman rightly noted Quadron were making their network TV debut, Coco also joined Tyler, the Creator on Late Night With Jimmy Fallon earlier this year. For more Quadron, check out their airy Avalanche collaboration with Kendrick Lamar, “Better Off.” The applause sign is illuminated.