Treahearn is credited on more than 91 international commercial music releases as mix engineer, composer, musician and assistant with some of the world's most successful artists including Madonna, The Black Eyed Peas, Oasis, Björk, Britney Spears, Gwen Stefani, Depeche Mode, Elbow[2][3] Massive Attack, Kylie Minogue, Britney Spears, Darren Hayes, Linkin Park, No Doubt, Dave Matthews, Keane, New Order, Janet Jackson, Natasha Bedingfield, Marilyn Manson, Girls Aloud, The Spice Girls and Turin Brakes.
Treahearn began his music career at Olympic Studios in London in January 2000, where he worked until 2007 as an assistant engineer to international producer/mixer Mark 'Spike' Stent.
[8] The track "Ice Cream" from Popstyles 1,[9] was picked up as the main theme music for Hong Kong's high rating TV series, Moonlight Resonance, and featured on the Asian Sony/BMG 2008 double CD compilation, Strawberry Love, alongside Whitney Houston, Avril Lavigne, Britney Spears and Christina Aguilera.
The lead track taken from the album, "I Don't Do Surprises", was a top 10 ARIA chart hit and was shortlisted in 2009 by APRA Industry awards for 'Most Played Australian Work'.
In 2010, Treahearn worked with Biffco in the UK on the ITV network The X Factor series 7, produced by FremantleMedia's Thames and Simon Cowell's production company SYCOtv.