Her itinerary also includes appearances at two Southern California shows billed as "Return to Sin City: A Tribute to Gram Parsons," in memory of the late country artist, who died more than 30 years ago. Others scheduled to perform at the July 9 and 10 shows are John Doe, Steve Earle, Eastmountainsouth, Kathleen Edwards, Jay Farrar, Jim James of My Morning Jacket, Norah Jones, Jim Lauderdale, Raul Malo and Dwight Yoakam.

Williams is touring by her latest album, "World Without Tears," which she released in April of 2003. The set was produced by Mark Howard (Bob Dylan, U2), whom Williams credits with convincing her that her new batch of songs needed a raw, stripped-down sound.

"Everything was so spontaneous and emotional," she said in a statement. "We recorded the album in this huge 1920s mansion right in the middle of Los Angeles. We recorded the way a live band would record."

Backing Williams in the studio were Doug Pettibone (guitars), Jim Christie (drums, percussion, keyboards) and Taras Prodaniuk (bass).

Williams' 1998 album "Car Wheels on a Gravel Road" won a Grammy for Best Contemporary Folk Album. She followed it up with 2001's "Essence."