Blue (Billie Eilish song)

The song is a reworking of two tracks Eilish had previously written, "True Blue" and "Born Blue". "True Blue" was one of the first songs she and Finneas had ever written, after "Ocean Eyes", which she performed along with that song in some of her earliest performances.^[1] In February 2022, the song was leaked online and went viral on TikTok, leading Eilish to decide to complete and release a finalized version of it.^[1][2]

"Born Blue" was a song that the siblings started writing for Happier Than Ever (2021), initially putting it on an early draft of the tracklist, but they ended up only writing a few lines for the song and never finishing it. They decided to combine both "True Blue" and "Born Blue" to reflect how they felt while writing Hit Me Hard and Soft and subsequently retitled the song to simply "Blue".^[1]

The song starts with an ethereal tone, discussing feelings of sadness and heartbreak as well as referencing every song in the album, and then moves into a dark section with her voice being distorted to a deeper octave.^{[citation needed]}

The melody is used as a leitmotif throughout the album to tie the themes together and make the album feel more cohesive. The melody of "Born Blue" can be heard in the tracks "Skinny" and "The Greatest", and the melody of "True Blue" is in the outro to "Bittersuite" leading into the beginning of this song.^{[citation needed]}

A "soft" indie rock^[3] and synth-pop song,^[4] "Blue" ends with the line "But when can I hear the next one", which has led to speculation that this was hinting towards a sister project or sequel to Hit Me Hard and Soft.^[5][6][7]