year sadly." Natalie Bassingthwaighte announced her departure on her Twitter account on 29 April 2015. On 1 May 2015, Redfoo announced on his Facebook page that he would also not be returning as he wanted to focus on other projects including a new album. Dannii Minogue was the only judge from season 6 who returned. On 3 May 2015, it was confirmed that Guy Sebastian would be returning to the judging panel, after a two-year absence, as Redfoo's replacement, while James Blunt and Chris Isaak would be replacing Keating and Bassingthwaighte. Isaak said, "It is going to be surreal to be on the show as a judge after having watched so many episodes as a fan. I know it's a show with a history of articulate, intelligent judges, and I know they wanted to change that up so they called me." Blunt previously appeared on season 6 as a guest mentor for Minogue's Groups category during the home visits round. Selection process Auditions Open auditions in front of the show's producers took place in 13 cities and ran from 31 January 2015 to 10 March 2015. Online auditions were also held for those who could not attend the open auditions. The auditionees chosen by the producers were then invited back to the last set of auditions that took place in front of the judges and a live studio audience. These auditions were filmed at the Qantas Credit Union Arena in Sydney on 4, 5, 6 and 7 June 2015 and Hisense Arena in Melbourne on 12, 13 and 14 June 2015. Bootcamp and five seat challenge The bootcamp round of the competition was held at the Sydney Olympic Park. Filming began on 8 July 2015. The episodes with a live audience were filmed on 10 and 11 July 2015. Before bootcamp started, the judges cut half of the 100 successful acts from auditions and only 48 acts remained (12 in each category). At the beginning of the bootcamp round, each judge found out which category they would be mentoring. Isaak was given the Boys, Blunt was given the Over 25s, Sebastian was given the Groups and Minogue was given the Girls. For the first time on The X Factor Australia, bootcamp incorporated the five seat challenge, where each act performed in front of the judges and a live audience to earn a place on one of the five seats in