its predecessor, universal acclaim met Kala's release in August 2007 and the album earned a normalised rating of 87 out of 100 on Metacritic. Kala was a greater commercial success than Arular. To support Kala, M.I.A. performed at a series of music festivals on the Kala Tour featuring performances in Europe, America and Asia. She performed three dates opening for Björk in the US and France. In 2008, M.I.A. provided guest vocals on Buraka Som Sistema's kuduro song "Sound of Kuduro", recorded in Angola with an accompanying video. The same year, M.I.A. and director Spike Jonze filmed a documentary in Woolwich, South London, in which they both appeared with Afrikan Boy, a Nigerian immigrant rapper and she disclosed plans to launch her own record label, Zig-Zag. She ended the year with concerts in the United Kingdom. By year end, Kala was named the best album of 2007 by publications including Rolling Stone and Blender. Metacritic reported in 2010 that Kala was the tenth Best-Reviewed Electronic/Dance Album on the website of the 2000–09 decade, one position below her debut album Arular. M.I.A. performed on the People vs. Money Tour during the first half of 2008. She cancelled the final leg of her tour in Europe through June and July after revealing her intentions to take a career break and work on other art projects, go back to college and make a film. In 2008, M.I.A. started her independent record label N.E.E.T. Recordings. The first artist signed to the label was Baltimore rapper Rye Rye, who performed with M.I.A. at the Diesel XXX party at Pier 3 in Brooklyn in October 2008 where it was revealed that M.I.A. was pregnant with her first child. During her performance at the 2008 Bonnaroo Music Festival, M.I.A. announced it was her “last show ever”, following by cancelling a British tour and saying she would then focus on recording new material. However, a few days afterwards Danny Boyle called her, wanting her to collaborate with A. R. Rahman in the score of his film Slumdog Millionaire. The result was the song "O... Saya", for which M.I.A. was nominated for an Academy Award for Best Original Song and a World Soundtrack Award for Best Original Song Written Directly for a Film for the song. M.I.A. was due to perform at the Oscars ceremony two weeks after her Grammy Award performance, but could not as she had just