"Bye Bye" is a song by American singer-songwriter Mariah Carey, taken from her eleventh studio album, E=MC² (2008). It was written by Carey, Mikkel S. Eriksen, Tor Erik Hermansen and Johntá Austin, and produced by the former three. It was released as the album's second single on April 15, 2008, in the United States, Australasia and select European countries. The song draws influence from pop and R&B music genres, and features a piano and keyboard-driven melody. Lyrically, the song features a dialogue in between Carey and her deceased father throughout the verses, and a universal salute to departed loved ones on the chorus, where she sings "This is for everybody, just lift your hands to the sky, cause we won't ever say bye bye".