The Triple J's Impossible Music Festival is a recurring event that has been broadcast on Australia's Triple J radio station over 55-hour periods in 2005, 2006, 2007 and 2008. Each event comprises 55 live music recordings from Triple J's music archives. The first went to air over 26–29 August 2005, to celebrate the 30 years worth of live music recorded by Triple J. The second was broadcast over 6–9 October 2006. The third was aired over 25–27 May 2007. The fourth was recently aired across 19–21 September 2008.
The lineup is selected by Triple J listeners voting for over 1000 live recordings made by Triple J. The recordings included music from festivals, concerts, smaller pub gigs, bands playing live in the studio, and some special events where listeners were able to win tickets to see the band for free in a secret location.