Multiple dates were also recently added in Florida and California. A few Canadian provinces round out the coast-to-coast itinerary, which stretches into mid-December. Details are included below. Overseas shows can be found at Amos' website.

The singer/songwriter/pianist is supporting her ninth studio album, "American Doll Posse," which debuted at No. 5 on The Billboard 200 when it surfaced in May. The 23-song set introduces a quartet of alter-egos that represent different aspects of Amos' personality.

During her performances, Amos channels each alter-ego--the outwardly political Isabel, the emotionally wounded but idealistic Clyde, the warrior Pip and the sensualist Santa--which come complete with their own looks. Each character also has its own blog space at Amos' website.

"American Doll Posse," which follows 2005's "The Beekeeper," was written and produced by Amos and recorded at her own Martian Engineering Studio in Cornwall, England. It is available in a limited-edition version that includes five collectible postcards, a 36-page booklet and a DVD with behind-the-scenes footage. A few songs from the set are streaming at Amos' MySpace page.

The Grammy-nominated performer is also expected to release a series of official live bootlegs recorded during her fall tour, according to reports.