And we’re back. After a couple of slow weeks for music on TV, the late-night talk shows returned in force Monday — and with a full slate of performers. The National were undoubtedly the kings of the hill, recruiting a choir, strings and guitarist Bryce Dessner’s wife Mina Tindle to help them play Oblivions on The Tonight Show Starring Jimmy Fallon. And that wasn’t the only music on Fallon; swinging the pendulum all the way to the other side of the musical spectrum, The Jonas Brothers performed their single Sucker on classroom instruments with an assist from The Roots. Things took a trip to poptown by way of balladeerland after that, with Noah Kahan making like Paul Simon with his bouncy Cynic on Late Night With Seth Meyers, King Calaway ticking the country-pop box with World for Two on Jimmy Kimmel Live and British crooner Lewis Capaldi serenading the masses with Someone You Loved on The Late Late Show With James Corden — who invited him to return the next night to sing again. Many happy returns.