Girl/guy pop teams have a long, often campy history: Lionel Richie & Diana Ross’ “Endless Love,” Kenny Rogers & Dolly Parton’s “Islands in the Stream,” Barbra Streisand & Neil Diamond’s “You Don’t Bring Me Flowers.” But lately they’ve become more cool than camp.

A handful of rock stars (and film stars) have paired up to croon artfully. But with so many underground rockers and A-list actresses teaming up, it’s hard to tell just who’s doing what with whom and for how long. Let us help.