Declare Independence
Björk did not tour again until the Volta Tour in 2007, supporting her sixth studio album. The tour lasted two years, during which she returned to perform in Oceania and South America after more than 10 years. She once again was the headliner of major international music festivals, including Coachella, Glastonbury Festival, Big Day Out and Roskilde Festival. The tour faced many controversies due to Björk's support of Tibetan independence movement, Kosovo declaration of independence and Faroese independence movement during several performances of "Declare Independence". From 2011 until 2013, Björk embarked on her Biophilia Tour, a multimedia project which featured her seventh studio album and a series of residencies and workshops that used the eponymous app to teach children about science and musicology. The tour was documented by the 2013 documentary "When Björk Met Attenborough" and the 2014 concert film "", and featured her first performance in Africa, but was hindered by a series of vocal cords issues, for which the singer underwent surgery. Similar problems caused the cancellation of the last shows of her following tour, the Vulnicura Tour, which supported her 2015 eighth studio album. Following the schedule of her Björk Digital exhibition, the tour resumed with acoustic shows and festival performances in 2016 and 2017.