Treme Sunday at 10 p.m., HBO

David Simon’s portrait of New Orleans after Hurricane Katrina returns on Sunday for a third season. The music is great, the acting — by Melissa Leo (above), Wendell Pierce, Kim Dickens, and others — is engaging, and the atmosphere is authentic. At times, Simon runs the risk of sanctimony, as he turns New Orleans into a promised land of sorts. And the loosely interlocking story lines are beginning to wander too far and wide. Still, it’s a worthwhile hour.

From Dust to Dreams: Opening Night at the Smith Center
for the Performing Arts 9 p.m., Channel 2

The Smith Center in Las Vegas opens with a long list of performers, including Carole King, Merle Haggard, Jennifer Hudson, Martina McBride, Willie Nelson, John Fogerty, and Mavis Staples. Songs will include “You’ve Got a Friend” by King and Staples, “(You Make Me Feel Like) a Natural Woman” by Hudson, McBride, and King, and “Pancho & Lefty” by Nelson and Haggard. Neil Patrick Harris hosts, because he doesn’t have enough on his plate already.

Boston Metal 9 p.m., National Geographic

Recycling, Brockton style. Wicked.

King of Dirt 9 p.m., DIY

Odds & sods.

America’s Next Top Model 8 p.m., Channel 56

Alicia Keys visits. Dylan thinks about models.