All of the songs on
Leaving Through the Window were written by McMahon, with the exception of "Hurricane", "Fall" and "You're Gone" which were written by Josh Partington. "Punk Rock Princess", "Cavanaugh Park", "Straw Dog" and "Globes & Maps" feature string arrangements written by
Paul Buckmaster who conducted the 26-piece orchestra that performed them. Partington described the album as a "conglomeration of songs that were anywhere from three months to three years old ... like a greatest hits of our early stuff." Discussing the album's title, McMahon said they wanted a name that was connected to some of the tracks, namely, to two lines in "I Want to Save You". He added that they lines "kind of reference the kind of getting in and out without being detected so that's how we came out with that". Musically, the album has been classified as
alternative rock, It has been compared to works by bands like
Jimmy Eat World,
Cheap Trick, "I Want to Save You" is a character sketch of a girl who was mistreated by her partner. Discussing "Punk Rock Princess", McMahon said he was interested in a girl who liked
punk rock music while he was in high school. The song served as a metaphor for what was a frequent discrepancy between the pair, which McMahon described: "She was cooler than I was and she liked punk and I was this, like, squirrely kid in, like, a piano band." The song had initially began as a ballad. They almost named it "I Woke Up in a Van", but felt that it did not fit as well as car did. The song references a show the band played in
Poughkeepsie, New York at The Chance venue, It is about being bullied and using words to fight back. The track was not initially planned for release on the album and was meant to appear solely on the
Audioboxer EP. "If You C Jordan" and "If I Were a Terrorist, I'd Bomb the Graduation" were written during the same period in
time. The band wanted both tracks to on the EP as an introduction to their music. However, "Terrorist" was left off the release because of the
September 11 attacks; the group thought it would be in bad taste to use it. It lyrics reference space travel, which would continue to be an occasional theme in McMahon's songwriting. When Partington played the track for the band at practice, McMahon was enthusiastic about it. Sean Richardson of
The Boston Phoenix said Partington's lyrical form was "more introspective and harder-hitting than McMahon’s". it was named after a recreational area in
Lake Forest, California. The park serves as a benchmark for incidents while growing up, like hanging out with friends and getting into trouble. The pop punk track "Fall" is followed by two
indie pop songs, "Straw Dog" and "Good News"; the latter two, plus closer "Globes & Maps", showcased a sound that McMahon would later explore with his solo project
Jack's Mannequin a few years later. ==Release==