Ashlee Simpson Debuts New Song on Chicago Radio

02/21/2008 at 02:35 PM EST

Ashlee Simpson made a club-friendly turn with her Timbaland-produced single "Outta My Head (Ah Ya Ya)." But the singer is returning to rock with another new song, "Little Miss Obsessive," which she premiered on Chicago's KISS FM DreX Morning Show on Thursday. Starting over a mid-tempo piano line, the song opens up into a more rollicking chorus. "Little miss obsessive, can't get over it," Simpson sings. She duets with Tom Higgenson, the lead singer of Plain White T's, on the track. (Listen to the song here.)