A little bit country, a little bit rock ’n’ roll and a lot of whatever Rob Thomas is these days. It’s as good a way any to sum up Monday’s late-night TV musical segments, I guess. The country (well, heartland rock, really) was supplied by Lukas (Son of Willie) Nelson and his band Promise of the Real, who performed their single Bad Case on The Late Show with Stephen Colbert. The rock ’n’ roll came courtesy of Perry Farrell, whose thundering number Pirate Punk Politician — delivered on The Tonight Show Starring Jimmy Fallon — harkens back to his Jane’s Addiction days. And finally, well, Rob Thomas continued to be Rob Thomas, promoting his recent Chip Tooth Smile album by showing up Jimmy Kimmel Live with the gospel-flecked One Less Day (Dying Young) and the ballad Can’t Help Me Now. Yep, that pretty much says it all.