'MODERN FAMILY': Mitch and Cam get reacquainted with an old friend (guest star Rhys Darby), right, they can't stand but is now a big-time celebrity in Australia. (Matt Klitscher/ABC)

It’s the ol’ pull-at-your-heartstrings trick on “Survivor: Cagayan” (CBS at 8 p.m.) when the remaining castaways receive letters from home as a reward, and one castaway embarks on a secret, potentially game-changing stakeout mission.

“American Idol” (Fox at 8) has the top six performing classic country and rock-and-roll hits.

“Nature” (WETA at 8) takes a look at the snow monkeys residing in Japan’s frigid Shiga Highlands.

The “Modern Family” (ABC at 9) gang is in Australia, a place Phil was ordered to visit by his mother because she wanted him to go back to the place he was conceived. While Mitch and Cam schmooze with a familiar, local celebrity, Phil’s attempts to blend into his native culture are squashed by rejection.

RETURNING SHOW: “Dual Survival” (Discovery at 9) returns for Season 4 with Joe and Cody in Sri Lanka facing a leech-infested jungle.

Bellamy leads the search for Octavia, and Raven realizes the connection between Finn and Clarke on “The 100” (CW at 9).

SERIES PREMIERE: Ed Stafford is host for the five-part series “Marooned” (Discovery at 10), which tests his survival skills. The English explorer is stranded in the world’s harshest environments with nothing but a camera.

“Nashville: On the Record” (ABC at 10) has select cast members perform fan-favorite songs from the show and discuss their writing processes. Hayden Panettiere, Charles Esten, Clare Bowen and Sam Palladio are all scheduled to perform.

Elizabeth and Philip’s long-planned mission gets botched, and it affects them in different ways on “The Americans” (FX at 10), while Stan’s intense work life causes his personal life to unravel.

“Your Inner Fish” (WETA at 10) concludes with an episode titled “Your Inner Monkey,” an exploration into how traits evolved from the earliest primates and what we still genetically share today.

Actress Cameron Diaz and comedian Jim Gaffigan are on “The Tonight Show Starring Jimmy Fallon” (NBC at 11:35), with music from Future featuring Pusha T.

Actors Sally Field and Timothy Simmons come to the “Late Show With David Letterman” (CBS at 11:35), with musical guest Needtobreathe.

Actors Tim Allen and Ginnifer Goodwin swing by “Jimmy Kimmel Live” (ABC at 11:35), along with a musical performance from Foster the People.

Rachel Lubitz