In this issue, Ashlee Simpson's "Autobiography" debuts at No. 1 on The Billboard 200. By doing this, she one-ups big sister Jessica, who peaked at No.

In this issue, Ashlee Simpson's "Autobiography" debuts at No. 1 on The Billboard 200. By doing this, she one-ups big sister Jessica, who peaked at No. 2 with a special edition of her album "In This Skin." Considering the artists are targeting different audiences, this probably won't cause much strife between the siblings. Ashlee's sound—rock-tinged pop à la Hilary Duff—is attuned to what radio is playing these days. Lead single "Pieces of Me" is ascending The Billboard Hot 100. The album, produced by John Shanks (Sheryl Crow, Melissa Etheridge, Alanis Morissette), is chock-full of catchy songs, all co-written by Simpson. There's enough fodder—from frisky bad girl ("LaLa") to edgy naif ("Love Me for Me")—to keep "Autobiography" on the charts in the foreseeable future. We hope she won't try to outdo her sister by taking her rough-around-the-edges persona to the extreme.—KK