Singer-songwriters, special guests and stunning choreography. Wednesday’s late-night talk show musical segments were clearly brought to us by the letter S. Start with Timothy Showalter (a.k.a. Strand of Oaks) delivering his crunchy roots-rock single Ruby with help from Jason Isbell, Amanda Shires and members of My Morning Jacket on The Late Show With Stephen Colbert. Then head over to Late Night with Seth Meyers for James Bay’s earnestly romantic Peer Pressure. Follow that with southern gothic balladeer Sara Beth Tomberlin’s three-song set — including Seventeen, Any Other Way and I’m Not Scared — on Jimmy Kimmel Live. Then finish up with a fitting showstopper: Normani’s powerful, stylishly choreographed version of Waves — aided and abetted by four dancers and a cameo from 6LACK — on The Tonight Show Starring Jimmy Fallon. That’s damn close to letter perfect.