A mere five and a half weeks before the start of her "5 1/2 Weeks Tour" with gal pal and fellow songstress Alanis Morissette, singer/songwriter Tori Amos [ tickets ] announced plans to release a double album Sept. 21.

Titled ''To Venus And Back,'' the two-disc set will be split between a live album-featuring live versions of songs performed during the recently completed ''From The Choirgirl Hotel'' tour--and a disc of all original material.

New tunes include songs such as ''Bliss,'' that probes the intricacies of the father-daughter relationship and ''Glory of the '80's,'' an autobiographical number that chronicles Amos' time as an up and coming musician in Los Angeles.

In a posting on her official website (www.tori.com), Amos said she didn't head into the studio with plans for a new LP, but she wasn't about to ignore a little inspiration when it came along.

''I had originally thought we were tracking stuff for the B-Sides album, and all of these songs kept coming,'' Amos said. ''The writing gods decided to stop by, and you try and be there when the muse decides she wants to hang out with you.''

An expected 12 tracks will make the new studio disc, including an as-yet-unnamed single set to hit the airwaves on Aug. 6. Amos begins her tour with Morissette Aug. 18 in Ft. Lauderdale, Fla. at the National Car Rental Center Arena. The pair will play 25 dates together before closing the junket with a Sept. 26 show in Irvine, Calif.