On the eve of the annual CMA Fest in Nashville, Kristen Bell and Jason Aldean host the 2013 CMT Music Awards (CMT at 8), which celebrate the past year’s best country music videos. Eric Church, Luke Bryan and Miranda lead the nominations with four each, while Aldean, Kenny Chesney, Rascal Flatts and Florida Georgia Line all have three nods. Performances in the live show include Taylor Swift, Lady Antebellum, Keith Urban, Hunter Hayes, Carrie Underwood and more.

SERIES PREMIERE: ReelzChannel gets in on the reality show game with “Beverly Hills Pawn” (at 9), which features a Southern California pawn shop that sells lots of movie memorabilia.

RETURNING SHOW: The kids are back on “Toddlers & Tiaras” (TLC at 9), as pageant moms and their young daughters descend on the Disco Fever pageant in Louisiana on the Season 6 premiere.

SERIES PREMIERE: Former pageant girls Brook and Tara, who also happen to be best friends and roommates, try to kick their co-hosted home shopping network up a notch on “The Good Buy Girls” (TLC at 10), and simultaneously drive their boss crazy with their wacky antics.

SERIES PREMIERE: Investigation Discovery debuts another true crime series, “Southern Fried Homicide” (at 10), which despite its catchy title, looks at grisly crimes in the south.

RETURNING SHOW: “Through the Wormhole with Morgan Freeman” (Science at 10) always investigates deep questions, and in the fourth season premiere, it doesn’t get much deeper than this: When does life actually begin?

RETURNING SHOW: Chef Roblé Ali moves his crew to a new kitchen as “Chef Roblé & Co.” (Bravo at 10) kicks off Season 2 ready to cook for New York’s rich crowd throwing summer celebrations. First up: Fellow Bravo star Phaedra Parks (of “Real Housewives of Atlanta”) hires the team to cater a proper Southern tea party.

RETURNING SHOW: CMT uses its award show to launch Season 3 of “Redneck Island” (at 10:30), as 15 competitors arrive at a remote island to participate in challenges and ultimately win $100,000.

Actor Johnny Galecki is on “Late Show With David Letterman” (CBS at 11:35), along with musician John Mellencamp and author Stephen King; plus, a performance by Queens of the Stone Age.

“The Tonight Show With Jay Leno” (NBC at 11:35) hosts actor Danny McBride, reality star Khloe Kardashian Odom and musical guest the Wanted.

— Emily Yahr