OK, well, I'm listening to "Tear In Your Hand" for the first time, and the Ashlee song I might associate that with thematically isn't "Pieces Of Me" but "Autobiograpy" (Ashlee's "I walked a thousand miles while everyone was asleep/Nobody's really seen my million subtleties" in comparison to Tori's "I think there're pieces of me you've never seen"). My guess is that Ashlee came up with the idea for "Pieces" without reference to anything else. But Tori is the sort of singer Ashlee would listen to, and I can imagine her hearing "Tear In Your Hand" and thinking, "Yes, but there are no pieces of me that Ryan's never seen" - except the way "Pieces" appears chronologically in Ashlee's reality show* (and the chronology may have been manipulated), you get the sense that she hopes this is what will happen with Ryan, but the relationship is just getting underway. The Ashlee lyrics are way more articulate in regard to what the pieces actually are, of course. Watching the show you see that the idea for the lyrics were clearly hers and probably the anxious Monday, Tuesday, Wednesday stuff at the start, but I also got the impression that Kara (it's her one appearance) wrote a good deal of the middle: she assures Ashlee that she's using the song title as a guide. In any event, Tori's being thrown over while Ashlee, for once, is being accepted, even though she's moody, messy, restless, angry, and she crashes real hard. (But then Tori claims to be the black of the blackest ocean.) Another thematically similar song is Jess's "With You," from 2003 I think; it's a nice song though of course the words aren't one-tenth as complicated as Ashlee's, but anyway, with you (i.e., with Nick, at least that's what the video suggests) Jess can let her hair down and can say anything crazy [except she doesn't, at least not within our earshot] and wear nothing but a T-shirt and be herself, etc.; it sounds warmer than it reads. The thing is, the Monday, Tuesday, Wednesday stuff in "Pieces Of Me" gives the song something a plot, so you actually understand her joyous relief and release when on the Tuesday following the sleepless Wednesday she fades into his arms and finally breathes.

[*Incredible episodes three and four (S01E03 and S01E04) of the Ashlee Simpson Show, if you haven't seen them.]