TV TOP PICKS

6 p.m. on ABC American Idol

For the first time ever, a live coast-to-coast vote by the American viewing audience will determine the winner of Season 17 (the second on ABC) of this reality competition series, with all of that voting taking place during the course of tonight’s three-hour live finale. Expect some musical performances by A-list musical guests, as well as final comments from judges Katy Perry, Luke Bryan and Lionel Richie, before this season’s Idol is crowned.

6 p.m. on AP The Aquarium

This new docu-series takes viewers inside one of Atlanta’s hottest tourist attractions: the Georgia Aquarium, a 10-milliongallon facility that’s home to thousands of aquatic creatures. This series spotlights several of those creatures, as well as the bond that some of them develop with the staff charged with their welfare. Georgia Aquarium’s ongoing efforts to protect aquatic species in nature also are highlighted.

7 p.m. on PBS Call the Midwife

As Season 8 draws to a close, Sister Hilda (Fenella Woolgar) digs deep to help a terminally ill patient realize her long-held dream of attending a dance. Elsewhere, the heartbroken Turners (Stephen McGann, April Brown) steel themselves to say goodbye to May, but their fortunes take a turn. Valerie and Trixie (Jennifer Kirby, Helen George) testify in court.

7 p.m. on CW Supergirl

Lex Luthor (guest star Jon Cryer) descends like a judgment upon Washington, D.C., and summons Lena and Lillian Luthor (Katie McGrath, guest star Brenda Strong) to the White House in the Season 4 finale “The Quest for Peace.” Realizing she has just one last shot to stop Lex, Supergirl (Melissa Benoist) turns for help to a resource she knows very well from her nonsuperhero day job: the power of the press.

10 p.m. on HBO Game of Thrones

HBO’s Emmy-winning megablockbuster adaptation of George R.R. Martin’s epic fantasy concludes Season 8 tonight as the battle for the Iron Throne of Westeros reaches its climax. Kit Harington (pictured), Emilia Clarke, Peter Dinklage all star.