1) “One World: Together at Home,” 2-8 p.m. ET on streamers (YouTube, Facebook, etc.), 8-10 p.m. ET on ABC. CBS, NBC and CW. Here’s a music mega-show, with Lada Gaga lining up top stars, including Taylor Swift (shown here), Stevie Wonder, Paul McCartney, Billie Eilish and Eddie Vedder. Other musicians, working from home, include Alicia Keys, Camila Cabello, John Legend, Keith Urban, Kacey Musgraves and more. Jimmy Fallon, Jimmy Kimmel and Stephen Colbert co-host the network part.
2) Nature shows, cable. Wednesday will be Earth Day … and the 50th anniversary of the original celebration. That will be big on PBS and several cable channels – two of which also celebrate the planet today. BBC America reruns its magnificent “Seven Worlds, One Planet” from 2-9 p.m., repeating some of it at 10:23. Nat Geo Wild celebrates natural America from 7 a.m. to 4 p.m. ET, Later, it has “Alaska Animal Rescue” at 9 p.m. ET, then debuts “Jungle Animal Rescue” (in India) at 10:03.
3) “9-1-1,” 8 p.m., Fox. The call center workers are taken hostage. It’s a rerun, as is “24 Hours to Hell and Back” (9 p.m.), with Gordon Ramsay trying to rescue a family restaurant in Richmond, Va.
4) “Frankie Drake Mysteries,” 7 p.m ET., Ovation, and/or “Line of Duty,” 10 p.m., AMC. This may be the time to sample popular crime shows from other countries. Be warned, however, that these two are opposites: “Frankie” is a gentle Canadian series about women detectives in the 1920; it’s light and bright, but its plots – especially tonight’s – are flimsy. “Line of Duty” is a British cop show, dark and intense. Tonight’s hour, the third of five, finds a cop (Lennie James) scrambling to cover his misdeeds.
5) “Saturday Night Live,” 11:29 p.m., NBC. Last week’s new episode, filled with at-home comedy bits, had lots of flaws but was still a welcome experiment; ratings were strong. Now we’re back to reruns; the onscreen note said it will be the John Mulaney episode, but NBC later listed Daniel Craig.