Christopher Andrew Joannou (born 10 November 1979) is an Australian musician best known as the bassist for the Newcastle-based alternative rock band Silverchair, and is a twin to sister, Louise Kipa. He was the first of the three band members to cut his long hair short. Joannou was nicknamed 'Lumberjack' by Silverchair fans for his love of trees, and plaid shirts. His bandmate Ben Gillies taught him how to play bass guitar. As well as being a well known bassist, Joannou was the assistant producer for The Mess Hall albums Feeling Sideways and the ARIA award-winning Notes From A Ceiling. He has used mainly G&L and Fender Precision Basses, and almost exclusively uses Ampeg B-15 Portaflex combos. As reported to gearwire.com, Joannou uses an Ampeg SVT-2 into an Ampeg 810 cabinet and a new Ampeg B-15 combo in his live set-up. In 2006, Joannou spoke at the launch of a mental health scholarship set up to honour his cousin, Nathan Trepezanov, who had committed suicide at the age of 21 in January of that year. Joannou is descended from Greek Slavophone (Macedonian) immigrants from Greek Macedonia.