Nothing kills spontaneity like anticipation and preparation. But of course sometimes it takes practice for things to look casual. There lies the fatal contradiction behind “Mobbed” (8 p.m., Fox).

The “Mobbed” in the title refers to the Flash Mobs of Internet lore. YouTube is rife with amusing clips where folks seem to casually gather in train stations to perform an elaborately choreographed number from “The Sound of Music,” or some other audacious act. These time-wasting snippets are fun to watch, but if you had to sit through an hour-long “Making of the Flash Mob Moment,” you’d begin to approach the tedium of “Mobbed.”

“Mobbed” also involves an emotional hijacking of a rather sweet if baffled couple. More than any other show, “Mobbed” makes a deal with a reality series seem like a Faustian pact. And who better than Howie Mandel to play the devil? As the show begins, we meet a somewhat sheepish dude who wants to impress a girlfriend who harbors some feelings of jealousy about his history of wandering ways. According to the logic of “Mobbed,” ambushing a woman with a giant song-and-dance spectacle is the fastest way to change her mind and win her heart.

But Mandel keeps upping the emotional ante. It’s not enough to have hundreds of dancers on hand. Howie browbeats his young charge into proposing on camera. No, make that get married on camera!

This snowballing nightmare might be entertaining as part of some dark drama. But instead, we’re stuck watching the nuts and bolts of putting on such a big show. This is where “Mobbed” departs from other Fox successes, like “Idol” and “Glee,” spectacles long on razzle-dazzle that don’t burden their audiences with inside glances at how the showbiz sausages get made.

• Nothing says razzle-dazzle like the musical version of a hospital drama. Tonight brings us “Grey’s Anatomy”: The Musical Event” (8 p.m., ABC) a series of flashbacks set to song. Not to be confused with the “Singing Detective” episode of “Chicago Hope.”

• “Taxidermy USA” (9 p.m., Discovery) profiles three families known for stuffing and mounting dear departed critters.

• On a similar note, alligator hunters prepare for a new season of “Swamp People” (9 p.m., History).

• “True Crime with Aphrodite Jones” (9 p.m., Investigation Discovery) enters a second season of second looks at famous crimes.

Tonight’s other highlights

• After last week’s save, two go home tonight on “American Idol” (7 p.m., Fox).

• The Dodgers host the Giants in Major League baseball action (7 p.m., ESPN). Happy opening day!

• The unit passes a morbid milestone on “CSI” (9 p.m., CBS).

• On two episodes of “The Office” (9:30 p.m., NBC), Jim’s uncomfortable moment (8 p.m.), Michael’s movie project (9:30 p.m.)

• A UFO believer expires on “The Mentalist” (9 p.m., CBS).

• Jack blames Canada on “30 Rock” (9 p.m., NBC).