All in the family

David Letterman may be retiring, but he's still hip to "the webs." "Legends on Letterman," a new limited online music series, kicks off with Mumford & Sons, which made its late-night TV debut on Letterman in 2010. 7 p.m. CBS.com

Lofty expectations

In the season finale of "New Girl," Coach finally moves out of the loft, leaving room for — Regis Philbin? Well, not exactly, but the veteran host does make an appearance. In the meantime, Jess and Nick appear to be back playing will-they-or-won't-they? 8 p.m. KMSP, Ch. 9

Deeper into the disease

"Frontline" investigates the Ebola epidemic and the numerous missteps that were made in trying to contain it. This is the program's follow-up to a September 2014 edition on the same topic. 9 p.m. TPT, Ch. 2

Neal Justin