Haven't seen the filum (as we say in Dublin) might try to track it down here in the depths of France. Glen Hansard is a fairly well established musical performer in Dublin with a career going back 15 years or so.
It's not his first appearance on celluloid, of course - as he was the ginger-haired guitarist in Alan Parker's adaptation of Roddy Doyle's novel 'The Committments' from the early 90s.
Apparently he doesn't like to be reminded of this fact, though - I think he lived to regret having accepted the part.