TONIGHT'S MUST-SEE

"Grey's Anatomy," 8 p.m., ABC. Tonight brings the start of a two-parter, with new episodes! George's dad pulled through the heart surgery, but now the cancer surgery begins.

"Nashville Star," 10 p.m., USA Network. In its first four seasons, this talent contest has offered some talented singer-songwriter-instrumentalists. Now come some changes. At the judging table, only Anastasia Brown remains. She's flanked by Blake Shelton and Randy Owen of Alabama. The terrific Cowboy Troy returns as co-host. Wynonna, who was so-so last year, is replaced by Jewel. Things start fast with the 10 finalists already chosen. They range from 18 to 36, from Chicago to Louisiana Cajun, from a former Marine to an eighth-grade dropout. In a first, a brother and sister are competing. Zac Hacker is 23, barely starting out; Angela Hacker is 29, a single mom who sees this as a last chance. "Star" producer H.P. Owens said both learned lessons from their dad, a musician fighting alcohol and drug addiction.

OF NOTE

"Ugly Betty," 7 p.m., ABC. The relationship between Daniel and Sofia (series producer Salma Hayek) faces a new obstacle.

"Armed & Famous," 7 p.m., CBS. Here's the second round of this reality show, in which semi-celebrities train and work with police in Muncie, Ind.

"My Name is Earl," 7 p.m., NBC. All of the key characters take turns being narrators tonight, offering various versions of who stole Earl's stolen treasure.

"Scrubs," 8 p.m., NBC. As new roommates, Dr. Cox and the janitor clash quickly. Meanwhile, Elliot seems like an ideal roommate (at first) for J.D.; with her private-practice money, she's able to spiff up the place.

"CSI: Crime Scene Investigation," 8 p.m., CBS. This rerun deals with several serious assaults. Greg intervenes in one with disastrous results.

"Stark," 9 p.m., CBS. An 8-year-old girl has been kidnapped and killed, echoing a similar case in which Stark was on the defense.

"ER," 9 p.m., NBC. When Gates (John Stamos) moves out of Meg's apartment, her response is extreme.

"Men in Trees," 9 p.m., ABC. Justine Bateman guests as Jack's ex-girlfriend, who still lives in Elmo and complicates his life.