Reality shows pop up and reintroduce themselves so frequently that they don’t even call them “seasons” anymore. According to the network, we’re now on the 10th “cycle” of “America’s Next Top Model” (7 p.m., CW). And that’s somehow fitting. A season is something that adheres to the rhythms of nature. A baseball season is a season. It begins with the first hint of spring and expires when there’s a threat of frost on the pumpkin. A mere cycle, on the other hand, can be repeated and reset at will.

It’s hard to tell whether “Top Model” is in its spin cycle or merely settling into a deep rinse.

Cycle 10 begins with a glance back at the first nine installments, complete with a recap of bar fights, insults, bad-hair days, gravity-defying photo shoots and catastrophic catwalks.

Thirty-five worthies arrive at a prep-school setting, where they are forced to change into identical schoolgirl outfits and listen to their headmasters, Jay Manuel and J. Alexander. Both do a credible job of playing the stern taskmasters, with Alexander lecturing the women in a deep voice while peering down from an absurd set of half-glasses.

Just when “Model” seems most absurd and formulaic, deep profundity breaks out all over.

One of the contestants, a striking young woman born in Somalia, says she was “circumcised” at the age of 7. Her discussion of the cultural rite of genital mutilation not only drags this show away from its more frivolous extremes but also raises awareness of a serious subject that would probably be ignored if discussed on a more sober and high-minded program. This judicious mingling of a grim message with effervescent escapism is a testament to the skills and smarts of Tyra Banks, who serves as both host and producer.

¢ “Great Performances” (8 p.m., PBS, check local listings) presents the 2007 Broadway revival of the 1970 Stephen Sondheim/George Furth musical “Company,” the tale of five married couples as seen through the eyes of a confirmed bachelor. In this production, directed by John Doyle (“Sweeney Todd”), each performer doubles as an orchestra member, bringing all of the instruments and music onstage.

Tonight’s other highlights

¢ The top-12 female contestants complete on “American Idol” (7 p.m., Fox).

¢ A former Wilson Phillips star proves that even celebrities need the “Supernanny” (8 p.m., ABC).

¢ “Mythbusters” (8 p.m., Discovery) celebrates its 100th episode with a few tricks out of the “MacGyver” playbook.

¢ “Ghost Hunters International” (8 p.m., Sci Fi) visits Frankenstein’s castle.

¢ “American Greed” (8 p.m., CNBC) looks at Scientology-related scams.

¢ A transplant patient needs help on “Deserving Design” (8 p.m., HGTV).

¢ Sophie recalls her accident on “In Treatment” (8:30 p.m., HBO).

¢ A doctor’s killer may have targeted another physician on “Law & Order” (9 p.m., NBC).

¢ Juliet proves no pushover to a corporate takeover artist on “Cashmere Mafia” (9 p.m., ABC).

¢ All of the rejected designers return for a season-four reunion on “Project Runway” (9 p.m., Bravo).

¢ A Hollywood therapist (Alexandra Wentworth) with a few problems of her own treats a celebrity clientele that includes Ahmet Zappa on “Head Case” (9 p.m., Starz).