1) “The Voice” semi-finals, 8-10 p.m., NBC. A week from the finale, “Voice” is down to eight acts – three on Blake Shelton’s team, two each with Kelly Clarkson and John Legend, only one with Ariana Grande. Now they perform and viewers vote; on Tuesday, five – tonight’s top four and one instant save – will advance. Tonight is all-music for NBC, with Michael Buble (shown here in a previous year) offering a special at 10, marking the 10th-anniversary of his best-selling Christmas album.
2) “A Very Boy Band Holiday,” 8 p.m., , ABC. And more music: In the boy-band era, guys kept merging into groups. This reunion has all the 98 Degrees guys (Nick and Drew Lachey, Justin Jeffre and Jeff Timmons) and more. There are three from ‘Nsync (Joey Fatone, Lance Bass, Chris Kirkpatrick); Bobby Brown and Michael Bivins of New Edition; Wanya Morris and Shawn Stockman of Boyz II Men; Erik-Michael Estrada of O-Town; and Joey McIntyre of New Kids on the Block.
3) “The Big Leap” season-finale, 9 p.m., Fox. Here’s the hour the show-within-a-show has led to – the “Swan Lake” ballet, performed by novices chosen in a reality show. It’s been a busy litt5le season: Paula died of cancer … Mike, her new boyfriend, reluctantly continued … Gabby broke up with Reggie, who returned to football, but now is trying to get back in time for the show … And Gabby changed the ballet’s ending. Also, Nick (Scott Foley), the producer, has shown hints of a conscience.
4) “Under the Vines,” any time, www.acorn.tv. Charles Edwards often fills British stereotypes. In “Downton Abbey,” he was the editor who romanced Edith, then died; in “The Crown,” he’s the older version of the queen’s secretary. Now he plays an Englishman who botches his life, then inherits half of a New Zealand winery. The other half goes to an Australian socialite; they have nothing in common except a lack of knowledge about wine or work. The result is a fairly entertaining six-part series.
5) ALSO: At 8 p.m., Fox’s “9-1-1” has its “mid-season finale,” with a burst of Christmas Eve crises; next month, “9-1-1: Lone Star” gets the timeslot. And at 9, ABC has a transplanted, two-hour “Bachelorette”; this is the “men tell all” episode with the show returning to Tuesdays next week.