"Bittersweet" is a single by the cello rock band Apocalyptica in collaboration with Ville Valo (of HIM) and Lauri Ylönen (of The Rasmus). The music is by Apocalyptica, the lyrics by Ville Valo and the vocals by Ville Valo and Lauri Ylönen. The song is written for four cellos (quartet) and voice, but there are versions for just the cello quartet. The name "Bittersweet" reflects in the song itself, with Ville singing the "bitter", and Lauri singing the "sweet".
"Bittersweet" was released on 29 November 2004. The song peaked at #1 on Finnish Singles Chart. It also peaked at number 6 in Germany, #8 in Switzerland, #11 In Austria and #53 in Sweden.
The band produced a video clip for the song "Bittersweet", shot in the band's hometown Helsinki and directed by renowned finish director Antti Jokinen, which had previously worked with artists such as Nightwish, Celine Dion, and Shania Twain. The video opens with Ville Valo and Lauri Ylönen sitting at opposite ends of a long table with red candles at each end, using a ouija board as they both sing. Occasional clips of Apocalyptica playing in a misty forest at what appears to be mid morning are strewn randomly throughout the video. As the video progresses the camera follows a woman dressed in black occasionally flashing back to Valo and Ylönen still singing. The woman runs through the same forest Apocalyptica is playing in, later Apocalyptica is shown playing upside down on the ceiling where Valo and Ylönen are sitting with their hair dangling just above them as they (being Valo and Ylönen) continue moving the dial of the ouija board. In the last few seconds of the video, the song ends and the woman is shown laying down to sleep as the moon descends into the horizon. Suddenly the candles at the table blow out, and the video ends with Ylönen and Valo glaring at the camera with wholly black eyes, presumably having been possessed by demons.