1) “Finian’s Rainbow” (1968), 10:30 p.m. ET, Turner Classic Movies. With many St. Patrick’s Day events canceled, people can settle for TCM’s full day of Irish films. Logically, there are two that John Ford filmed in his parents’ homeland – “Rising of the Moon” (1965) at 4:30 p.m. ET and John Wayne’s “The Quiet Man” (1952) ar 8. But no, you don’t have to be Irish: Before directing “Godfather” films, Francis Coppola made “Finian’s Rainbo,”(shown here with Fred Astaire and Tommy Steele), a gem of a musical with zesty visuals and bursts of satire.
2) “Empire,” 9 p.m., Fox. In your lifetime, how often have you seen a concert ended by a drunken fan or a jeering crowd? In this hour, it happens twice – another sign that “Empire” keeps going overboard. Yes, it has great music and gifted actors, but its stories are sheer excess. That’s clear tonight when the bi-polar Andre keeps arguing with his dead half-brother … who sometimes inhabits Andre’s body.
3) “Legends of Tomorrow,” 9 p.m., CW. The superhero world has been kind to Brandon Routh. He’s been Superman in a movie and as guests in two TV series; he’s been Ray Palmer – who shrinks into The Atom – on this series and three others. Now Routh is leaving “Legends,” as is Courtney Ford, his wife on the show (as Nora Dahrk) and in real life. In this episode, they take a final mission. It’s a fun hour, reminding us that superheroes get to meet Shakespeare, but still must wait in line at the restroom.
4) “Networld,” 8-11 p.m., PBS (check local listings). The Internet began as pure democracy, Niall Ferguson tells us. And now? In their respective fields, Amazon has 40 percent of the action, Facebook has 70, Google has 90. They also have massive data on us. Ferguson wades through the history and science of networks, then has a chilling look at the recent past – Russian trolls stirring American discontent – and the future: Each year, China has 18 tech graduates for every one in the U.S.
5) ALSO: Setting up next week’s season-finale, “This Is Us” (9 p.m., NBC) has Randall reflecting on what could have been. Meanwhile, cable has comedies. In a quietly clever “Schitt’s Creek” (9 p.m., Pop), the bachelor party (in an escape room) has a surprising hero; in a warm and funny “Miracle Workers: The Dark Ages” (10:30 p.m., TBS), Prince Chauncley fumbles chances to date Alexandra.