Question: What banned formed in Olympia, Washington headlined the Decibelle music and cultural festival?
Sentence (from "The 25th National Cultural Festival Okayama 2010"): The festival will host 68 events such as the opening festival, orchestral music, choral music, brass band music, drama, literary, arts, dance, traditional Japanese music are held throughout the festival in all of Okayama Prefecture's cities, towns and villages.
Relevant evidence: No