It is the seventeenth countdown of the most popular songs of the year, as chosen by the listeners of Australian radio station Triple J.

[2] Controversy began when it was rumoured that the winner had been unintentionally leaked by the ABC.

The ABC Shop website promoted the February issue of Jmag with a description stating "Topping the 2009 countdown is Mumford & Sons' 'Little Lion Man'".

[2][3] Triple J neither confirmed nor denied the rumour with some even claiming it was a hoax, amounting to a clever marketing campaign.

Triple J's Hottest 100 Volume 17 is the compilation featuring the best of the Top 100 voted tracks on two CDs.