Manic and sort of off-putting with the off-beat drum pattern, and the piano part: it's like they add a pulse to the song. Damn, that chorus! I know Chantal from her work with Avril on UMS, and I can really imagine Avril singing this kind of music. A little bit darker and more introspective and lyrically emotional. Like that piano rock vibe, along the lines of Cristina Perri.
This is so great - the chord progression really makes the song too. So frenzied and dynamic.