On 8 March 2007, it was announced that judge Louis Walsh, who had appeared in all three previous series, had been sacked. This, along with the additional category, created vacancies for two new judges to join the original panel of Sharon Osbourne and Simon Cowell. Walsh was replaced by American choreographer Brian Friedman, who was hired after impressing Cowell on his show "Grease Is the Word". A fourth judge was also brought in: Australian singer, actress and "Australia's Got Talent" judge Dannii Minogue. Cowell hired Minogue after viewing tapes of her judging on "Australia's Got Talent", and because of her 30 years experience as a singer and performer.