What festival was the band that released 10,000 Days confirmed to headline on March 26?
After moving to Los Angeles, Keenan met Adam Jones who had in college heard him singing on a demo. Impressed with Keenan's vocals, Jones suggested that they form a band. Reluctant, Keenan eventually agreed and, in 1990, Tool was formed. Fronted by Keenan, the eventual lineup included guitarist Jones; his neighbor, drummer Danny Carey; and bassist Paul D'Amour, who would later be replaced by Justin Chancellor.
Tool signed to Zoo Entertainment in November 1991 and released the Opiate EP the following year. To support this release, the band toured with Fishbone and Rage Against the Machine.
Fifteen years after the band's formation, Tool had acquired what Dan Epstein of Revolver described as a devoted "cult" following, and in May 2006 the band released 10,000 Days, an album in which Keenan sang about more personal issues in contrast to previous attempts to inspire change. His mother, who inspired the song "Jimmy" on Ænima, also served as the inspiration for "Jambi", and the two-part song "Wings for Marie" and "10,000 Days (Wings for Marie, Pt 2)", which deals with her 2003 death after 27 years, or around 10,000 days, of suffering. The album sold 564,000 copies in its opening week in the U.S. and was No. 1 on the Billboard 200 charts. However, 10,000 Days was received less favorably by critics than its predecessor Lateralus had been.Following 10,000 Days, Tool has one album remaining to fulfill the obligation of its record contract. Though there is little information available on plans for this album, the band is steadily working towards its fifth studio release.  Tool has worked around Keenan and his side projects since 1999, starting with the creation of A Perfect Circle, which has led to several years between projects. Regarding the future of Tool, Keenan stated in a 2007 interview with Spin, "We'll make music together until one of us is dead."On March 24, 2009, a summer tour was announced on Tool's website, and in a March 26 press release Tool was confirmed as a headliner for the second annual Mile High Music Festival in Commerce City, Colorado, with Widespread Panic and The Fray. Tool also headlined Lollapalooza 2009 in Chicago, Illinois.On December 12, 2012, Tool's webmaster posted on the band website:
Mile High Music Festival