Purity Ring and Tegan & Sara will be among the acts competing for this year's Polaris Prize in Canada. They join the likes of Metric, Godspeed You! Black Emperor, Colin Stetson and Young Galaxy on the shortlist to find the nation's best album. The list was announced at The Drake Hotel in Toronto by Polaris founder Steve Jordan on Tuesday (16Jul13). The winner will be announced at a gala held in Toronto on 23 September (13). Feist won last year's $30,000 (£20,000) prize for her album Metals.