The title refers to Billy’s red Pontiac Firebird, which serves as the setting for many shared memories.
An "Alt Version" exists, which many fans find more melancholic and emotional. This version features a stripped-down arrangement where both Abbey and Billy contribute vocals, adding a layer of authenticity to the sibling narrative. Owl City's “Firebird” is Incredible – Here's Why Owl City - Firebird
The song serves as a nostalgic exploration of sibling bonds and the inevitable passage of time. While Adam Young is an only child, he wrote the track to capture the "special bond" he observed between Abbey and Billy. The title refers to Billy’s red Pontiac Firebird,
The lyrics emphasize that "everything changes," documenting the transition from building "homemade bombs" in the basement to moving away and starting families. Owl City - Firebird