"Who Is It" (sometimes "Who Is It (Carry My Joy on the Left, Carry My Pain on the Right)") is a song recorded by Icelandic singer Björk for her fifth studio album Medúlla. It was released as the lead single from the album on 18 October 2004 by One Little Indian Records. Björk wrote "Who Is It" during the recording sessions for her previous album, Vespertine (2001), when it was known as "Embrace Fortress"; she left it off the album it as she felt it came from "a different family". The final version features throat singer Tanya Tagaq and beatboxer Rahzel, and lyrics reflecting the dialogue between mother and child. Critics praised "Who Is It" as exuberant and catchy. It peaked in the top five on the single charts in Spain and reached the top 30 in Italy and the United Kingdom. The music video was directed by Dawn Shadforth and shot outdoors in Iceland, and features Björk in a bell-shaped dress designed by Alexander McQueen. During the promotional campaign for Medúlla, Björk performed the song on a number of occasions, such as Friday Night with Jonathan Ross and L'Album de la semaine. She performed it on subsequent tours. It has been covered by Bon Iver and Kurt Elling. Background The initial version of "Who Is It" was written with artist Bogdan Raczynski. Björk approached him during a show in London in 2000, and months later, they met in New York and wrote a song titled "Embrace Fortress" during the final recording sessions for her fourth studio album Vespertine (2001). She decided not to put the song on the album, because she felt it was from "a different family"; according to Björk, Vespertine was "introverted and shy and not a very physical record", and she felt this was a physical song that she wrote when she was feeling strong again. Raczynski also said he did not want his version of the song to be available. He said "It was a beautiful thing we did together, but for that reason alone it should be left in the clouds. People need mystery and romance". However, it eventually received a limited vinyl release by Rephlex Records. Björk then approached the song again during the recording sessions for Medúlla and renamed it as "Who Is It". Electronic music duo Matmos also contributed to the song – they did "fruit-machine-noises" that are in the choruses