Gareth Farr was born in Wellington, New Zealand. He began his studies in composition and percussion at the University of Auckland in 1986. The experience of hearing a visiting gamelan orchestra in 1988 prompted his return to Wellington to attend Victoria University, where the characteristic rhythms and textures of the Indonesian gamelan rapidly became the hallmarks of his own composition.
Farr continued with postgraduate study in composition and percussion at the Eastman School of Music in Rochester, New York, where his teachers included Samuel Adler and Christopher Rouse.
In 1993, at the age of 25, Farr was appointed composer-in-residence by Chamber Music New Zealand, the youngest ever composer to hold that position. At the conclusion of the residence, Farr returned to the Eastman School to begin a doctorate in composition. As well as composing Kembang Suling (for flute and marimba, his most popular work to date) and three works for orchestra during this time, Farr also introduced audiences to his on-stage alter-ego, the percussion-playing drag queen Lilith LaCroix.