In the style of the boy band vocal bands of the time, Human Nature became Australia's most successful pop group of the '90s and beyond, outselling their international contemporaries Backstreet Boys, *NSYNC, and Boyzone. Andrew Tierney, Michael Tierney, Phillip Burton, and Toby Allen first joined up as the 4Trax in 1989 when they were all still attending a New South Wales agricultural high school. Andrew, Burton, and Allen were all in school performances of Godspell and Grease at high school, while Michael, Andrew's younger brother, sang in school choirs and performed in an o...