Carly Rae Jepsen made headlines recently with an epically bad first pitch at a Tampa Bay Rays game, but she signs on for something more her speed as a guest judge on “So You Think You Can Dance” (Fox at 8). The top 16 dancers perform.

The CW recruits one of its stars, “Vampire Diaries” actress Candice Accola, to be the guest star on “Whose Line Is It Anyway?” (CW at 8).

SERIES PREMIERE: The new reality series “Dallas Car Sharks” (Velocity at 8:30) follows the world of car flipping in Texas, as various dealers compete to outbid each other at automobile auctions.

The live shows start and a dozen acts perform on “America’s Got Talent” (NBC at 9), as the show moves to its new location at Radio City Music Hall.

RETURNING SHOW: The ancestry show “Who Do You Think You Are?” (TLC at 9), produced by Lisa Kudrow, had a good run on NBC — but not quite good enough to stay there. Now, TLC picks up the show. The fourth season kicks off as Kelly Clarkson takes a look at her family history.

SERIES PREMIERE: The new docu-series “The Vineyard” (ABC Family at 10) follows a group of 20-somethings working on Martha’s Vineyard for the summer, where all sorts of drama naturally surfaces.

In a strange twist, Pierce and Moretti have to use virtual reality to investigate a murder case on “Perception” (TNT at 10), which makes it even more difficult for Pierce to distinguish between reality and fantasy.

Harvey and Jessica team up on a case on “Suits” (USA at 10) but run into problems when a former nemesis hurts their defense strategy.

RETURNING SHOW: It’s the night of Lisa Kudrow: The actress returns as Fiona for the Season 3 premiere of “Web Therapy” (Showtime at 11). In the premiere, Fiona escapes to a resort with guest star Steve Carell, but her peace is quickly interrupted when her former beau (Alan Cumming) shows up, wanting forgiveness.

Actor Hugh Jackman, Kudrow (again) and musical guest Jason Isbell are on “The Late Show With David Letterman” (CBS at 11:35).

“The Tonight Show With Jay Leno” (NBC at 11:35) hosts actor Aaron Paul and singer Selena Gomez.

— Emily Yahr