Harwood was a member of the Chills from 1986 to 1990, during which time they had their biggest commercial success with the singles I Love My Leather Jacket (a New Zealand top 5 single) and Heavenly Pop Hit, which went to number 17 on the U.S. modern rock chart). During this time, The Chills also performed before their largest audience ever. They drew 60,000 people at the 1987 Glastonbury Festival.
After leaving The Chills, Harwood moved to New York, where he became a founding member of Luna. In 1996, Harwood joined forces with several noted members of indie rock groups to form a side-project, the semi-experimental band Tuatara - named, at Harwood's suggestion, after a type of reptile from his native New Zealand.