TONIGHT'S MUST-SEE

Academy of Country Music awards, 7 p.m., CBS. Top stars and acts perform, including George Strait, Kenny Chesney, Reba McEntire (who hosts), Brad Paisley and Vince Gill; Brooks & Dunn, Rascal Flatts, Sugarland, Little Big Town. Two former "American Idol" champions sing: Carrie Underwood, already near the top of Nashville, and Kelly Clarkson, a pop star making a visit. In between all that, awards will be handed out. Strait and Brooks & Dunn lead this year's nominees.

OF NOTE

"Veronica Mars," 6 p.m., CW (digital cable channel 93). An African man is trying to find the son who was taken from him, years ago. Veronica is hired to determine whether he's a student at her college.

"American Idol," 7 p.m., Fox. The final three singers perform. Tomorrow, we'll learn which two are in next week's finale.

"Dancing With the Stars," 7 and 8 p.m., ABC. First is an abbreviated rerun of yesterday's episode. Then is the results show, trimming to next week's final three.

"The Shield," 7 p.m., FX. In a powerhouse episode last week, Shane finally admitted to Vic that he's the one who killed Lem. Now Vic is ignoring him and Shane makes overtures to the Armenian mob. Meanwhile, the investigation of a mass killing continues, revealing a bigger issue.

"Nova: Hitler's Sunken Secret," 8 p.m., PBS. In 1944, Germany was shipping key ingredients from Norway, in its effort to build a super bomb. That's when the Norwegian resistance intervened, managing to sink the ship. This rerun tells that fascinating story and also has experts view another question: Would the bomb have really worked?

"House," 8 p.m., Fox. Don't you hate it when there's a chess brawl? This hour has a teen provoking a fight after a chess match. Also, House is suspected of sabotaging Foreman's job interview.

"Frontline: Spying on the Homefront," 9 p.m., PBS. Hedrick Smith looks at the steps the anti-terrorist effort takes to spy on people in the U.S.

"Law & Order: Special Victims Unit," 9 p.m., NBC. A teen seems to have a tape of a murder being committed. Is it real?