Pop-rock trio Semisonic will return with their third album, All About Chemistry, on March 6, and the first single, "Chemistry," is already earning play on alternative radio.

Frontman Dan Wilson said he wrote "Chemistry" after an off-the-cuff exchange with video director Sophie Muller, who directed Semisonic's video for "Secret Smile" (RealAudio excerpt), one of the singles from the band's breakthrough 1998 album, Feeling Strangely Fine, which also included the hit "Closing Time" (RealAudio excerpt).

"I was talking to [her] about working with people," Wilson said, "and how she decides to make a video with an artist. She said, 'I know within five minutes. It's all about chemistry,' and I was just struck by that."

"I thought that's really true," he said, "and it's true about a lot of things in life, and it just really made me want to write a song with that as the theme and idea."

"It was on the early side of songs written for the album," bassist John Munson said. "It was a riff that Dan had been playing for a while ..."

"On the piano," Wilson interjected.

"Yeah, this piano riff," Munson continued. "It kept kind of floating around and he'd go, 'Hey, check this out' and bang away at it."

"Don't know what to do with it," Wilson said, "but it sounds cool."

"It took us awhile to really get the hang of playing it," drummer Jacob Slichter said. "It seems weird, 'cause when I hear it now, it just sounds great."

"Yeah, it sounds pretty effortless," Wilson agreed, "but we kind of had to blow it a few times at first."

For the video to "Chemistry," the Minneapolis band worked with director Liz Friedlander, who also handled the Deftones' "Change (In the House of Flies)" and Blink-182's "Adam's Song."

"It's kind of [a tribute to] Rube Goldberg inventions," Slichter said of the video, which is expected to debut in the next few weeks. "Y'know, like that old game [Mousetrap], where you had to roll the ball into the bathtub that would make the man jump into the swimming pool and things like that."

In his "Invention" drawings, Goldberg rendered schematics and cross-sections of absurdly complex machines that would perform the simplest tasks. The late Pulitzer Prize-winning cartoonist's works included "Safety Device for Walking on Icy Pavements," "How To Tee up a Golf Ball Without Bending Over" and "How To Keep the Boss From Knowing You Are Late for Work."

"So, the video kind of plays off the idea that there are forces at work in the world," Slichter said, "and then there are people falling in love, meeting each other, having weird [situations]."

"And getting mad at each other," Wilson said.

"The randomness of it," Munson said.

"And like it's all being controlled by this machinery that's clunky and weird," Wilson said. "It was fun for us, 'cause all we had to do was rock, and everyone else did the filmlike acting parts."

After appearing at the Sundance Festival this week, Semisonic will head to the U.K. in February to open a tour with Texas, after which the band will return to the U.S. in March for a brief acoustic club tour.