“Glee” (8 p.m., Fox) has both promise and problems. It all comes down to tone. In music, as in television, tone is everything.

Take that from someone whose formal musical education consists of watching old cartoons with classical-music scores. One of my favorites was an old Looney Tunes featuring Elmer Fudd as a maestro leading ducks as they quacked their way through “The Blue Danube Waltz.”

I didn’t know it at the time, but this was a Warner Bros. knockoff of Disney’s “Fantasia,” a parody Bronx cheer aimed at Uncle Walt.

Disney has long inspired admiration, imitation and parody. And “Glee” continues that tradition. It shamelessly lifts elements from the “High School Musical” franchise. A handsome football player shatters clique boundaries by joining the glee club and living out his dream as a singer.

“Glee” just can’t decide whether it wants to indulge in the giddy uplift of musical theater or drown the whole enterprise in a “Carrie”-like vat of cynical Fox attitude.

At first, the Fox side wins out. Jane Lynch stars as a brutal and brittle gym teacher who lords over the savagely cruel cheerleaders. A music teacher is fired from school for fondling a male student and then turns to drug-dealing on campus.

At the same time, “Glee” focuses on the dreams as well as the marital woes of teacher Will Schuester (Matthew Morrison), who wants to relive past glee-club glories. Is he a dreamboat or merely a dreamer? An inspiration or a loser? It’s not difficult to see that Schuester’s heart is in the right place, but “Glee” has the hardest time deciding whether it’s “Mr. Holland’s Opus” or “School of Rock.”

• The 2008 documentary “Stranded: The Andes Plane Crash Survivors” on “Independent Lens” (9 p.m., PBS, check local listings) is the latest and most acclaimed film to recall the shocking 1972 true tale of the Uruguayan rugby team’s survival, endurance and cannibalism.

Filmmaker Gonzalo Arijon was a childhood friend of several of the men involved. Salon called it an “intimate, terrifying and positively riveting documentary.”

Tonight’s season finales

• There’s a showdown in the promised land on “NCIS” (7 p.m., CBS). For a show with no “buzz,” “NCIS” remains the most-watched drama on television.

• Jane may be falling into a trap on “The Mentalist” (8 p.m., CBS).

• A winner emerges on “Dancing with the Stars” (8 p.m., ABC).

• Adrianna delivers on “90210” (8 p.m., CW).

• A man vanishes after a midnight dip on “Without a Trace” (9 p.m., CBS).

Tonight’s other highlights

• Adam Lambert and Kris Allen compete on “American Idol” (7 p.m., Fox).

• Temperatures and prices drop on “Deadliest Catch” (8 p.m., Discovery).

• A judge reopens a 30-year-old case on “Law & Order: Special Victims Unit” (9 p.m., NBC).

• Tommy and Janet share a weekend on “Rescue Me” (9 p.m., FX).

• “REAL Sports with Bryant Gumbel” (9 p.m., HBO) looks at bull-riding.

• “Tori & Dean: Home Sweet Hollywood” (9 p.m., Oxygen) follows the former “90210” star’s family as they cope without their pug.

Cult choice

Teens discover a Cro-Magnon (Brendan Fraser) in the 1992 comedy “Encino Man” (7 p.m., Encore).