"Half Mast" - Empire of the Sun.
In a year packed with overrated and overhyped newcomers, only one act which popped up in many of the "Big in 2009" lists really stood out for me. Aussie duo Empire of the Sun have an image and a sound like no other band around these days. They recently enjoyed massive success at the ARIA awards (the Australian version of the Brits/Grammys), winning awards for best album, single, group, pop release and producer.
So it won't be too surprising that they will figure very significantly indeed in this chart. Their first appearance is with an album track which, like much of their sound, is hard to describe; it's keyboard-driven with a retro feel but is nowhere near as contrived as some of 2009's 80s revivalists.