Four new contestants are put to the test.

Four new contestants are put to the test in the first part of a two-hour episode.

Four new contestants are put to the test in the second part of a two-hour episode.

Four new contestants are put to the test in the first part of the two-hour season finale.

The season premiere episode features TV personality/actress/singer Kelly Osbourne, playing for the Sharon Osbourne Colon Cancer Program at Cedars-Sinai vs. singer/songwriter/actress JoJo, playing for The Hole in the Wall Gang; and former NFL star/Super Bowl champ/actor Vernon Davis, playing for the Vernon Davis Foundation vs. former NFL star/Super Bowl champ Victor Cruz, playing for the Victor Cruz Foundation.

Actress and television personality Jodie Sweetin ("Fuller House") plays for The Scleroderma Research Foundation vs. actor Frankie Muniz ("Malcolm in the Middle"), playing for the State Forty Eight Foundation; and gold medal-winning Olympic gymnast Laurie Hernandez plays both for the Alzheimer's Association and OneMind.org vs. five-time Olympic Medalist Nastia Liukin, playing for the Special Olympics.

Former "Beverly Hills 90210" sweethearts "Kelly" and "Steve" go note-to-note: Actress Jennie Garth, playing for the Equus Foundation vs. Actor Ian Ziering, playing for The Epidermolysis Bullosa Medical Research Foundation; and Grammy Award-winning artist Shaggy, playing for the Shaggy Make a Difference Foundation vs. Actress/Director Kim Fields ("The Upshaws"), playing for Back On My Feet.

Singer/songwriter Cassadee Pope, playing for Creative Waves Foundation vs. singer/actress Jana Kramer, playing for Safe Horizon; and actor/singer Tituss Burgess ("Unbreakable Kimmy Schmidt"), playing for Broadway Dreams vs. Spice Girl and singer/actress Mel B., playing for Women's Aid.

Four new contestants are put to the test.

This week's episode focuses on the universal theme of LOVE, as contestant Khalia, on the brink of engagement and from Tampa, FL, competes against newly engaged Ian from Los Angeles, CA; and then, Mark from New York, NY, competes against Christina from Las Vegas, NV, in a series of love-focused songs for the chance to win cash and potentially the $100,000 grand prize.

This week's episode celebrates rock and roll as contestant Janice from Garland, TX, competes against Tim from Taunton, MA, and then, Vince from Cleveland, OH, competes against Daniel from Sherman Oaks, CA, in a series of rock and roll tunes for the chance to win cash and potentially the $100,000 grand prize.

This week's episode is a blast from the past, as contestant Isaac from Los Angeles, CA, and Alexandra from Bronx, NY, guess tunes straight from the 1980s; and then, Brenton from Portland, OR, competes against Roisin from Fanwood, NJ, as they try to name a series of songs from the '90s for the chance to win cash and potentially the $100,000 grand prize.

It's movie night, as teacher Lori from Austin, TX, goes head-to-head with Dave from New York, who works in advertising. Round One is "Mixtape," and all the tunes are from the movies. The theme continues into the Bid-A-Note round, which concludes in a blockbuster ending. The Hollywood theme keeps coming as Chris, a legal assistant from Brooklyn, NY, takes on Kalisha from Minneapolis, MN, who works in digital marketing. Will either of them win the $100k grand prize?

The second hour features Sara, an executive assistant from Bronx, NY, who takes on Tye, a military veteran from Atlanta, GA. Sara shows her "New York mean," but will she beat the military vet for the big money in the Golden Medley? Next, Raymond, an accountant from Chicago, faces New Orleans entrepreneur and mom Lyndsey. Round One starts with a NAME THAT TUNE favorite, "Spin Me Round." The prizes stack up, and there's even an underwater scooter on offer! See who will sink and who will swim, as competitors slug it out to come out on top and win the $100,000 grand prize.

Celebrity contestants Chris Jericho, Adam Rippon, Todrick Hall and Sheryl Swoopes.

Craig Ferguson vs. Jack McBrayer and Tisha Campbell vs. Elizabeth Berkley.

Tyron Woodley vs Tiki Barber and Johnny Weir vs Tara Lapinski.

Celebrity contestants Jordin Sparks, Clay Aiken, Amber Riley, and Chris Colfer.

Celebrity contestants Andy Richter, Holly Robinson Peete, Michael Ian Black and Melissa Peterman.

Spice Girl Melanie C. vs. Darren Criss from Glee, and Olympian Lolo Jones vs. Carson Kressley from RuPaul’s Drag Race.

Sports stars take the stage as it's John Salley vs. Adam Rippon and Rashad Jennings vs. Todd Gurley.

Celebrity contestants Megan Hilty vs. Rumer Willis and Belinda Carlisle vs. Debbie Gibson.

Celebrity contestants Taylor Hanson vs. JoJo Siwa and Steve-O vs. Rachael Harris

Celebrity contestants Amanda Seales vs. Kate Flannery and Ross Matthews vs. Jessie James Decker

Michael Kosta vs. Jeff Ross and Tig Notaro vs. Nicole Sullivan