Rapper Shad, seen at the recent MuchMusic Video Awards in Toronto, is one of the nominees for this year's Polaris Prize. (Mark Blinch/Reuters) Past Polaris Prize winners Caribou and Owen Pallett are once again vying for the music world honour, which celebrates the best Canadian album of the year.

Organizers unveiled a short list of 10 finalists for the $20,000 prize at a midday ceremony in downtown Toronto on Tuesday.

They are:

• The Besnard Lakes, The Besnard Lakes Are the Roaring Night (Montreal).
• Broken Social Scene, Forgiveness Rock Record (Toronto).
• Caribou, Swim (Dundas, Ont.).
• Karkwa, Les Chemins de Verre (Montreal).
• Dan Mangan, Nice, Nice, Very Nice (Vancouver).
• Owen Pallett, Heartland (Toronto).
• Radio Radio, Belmundo Regal (Grosse Coque, N.S., Moncton, N.B., and Pointe-à-l'Église, N.S).
• The Sadies, Darker Circles (Toronto).
• Shad, TSOL (London, Ont.).
• Tegan and Sara, Sainthood (Vancouver and Montreal).

The finalists were whittled down from the eclectic, wide-ranging long list of 40 contenders announced last month and compiled out of nominations from almost 200 music journalists, critics, broadcasters and bloggers from across the nation.

The prize is determined solely by artistic merit, regardless of musical genre or an album's sales. A smaller panel of 11 judges, selected from the larger jury, will decide the winner.

"Once again our jury has selected a magnificently and satisfyingly diverse short list," prize founder and executive director Steve Jordan said in a statement.

Past Polaris-winner Dan Snaith, a.k.a. Caribou, is once again a nominee for his latest album, Swim. (Indoor Recess)"They've managed to reward continued artistic achievement from previous winners and nominees, while making room for both newcomers like Radio Radio, Karkwa and Dan Mangan, and veterans like Tegan and Sara and the Sadies. Our grand jury will have their work cut out for them selecting a winner."

Singer-songwriter Pallett was the inaugural Polaris winner in 2006, for his album He Poos Clouds (released under his performance moniker Final Fantasy). Electronic musician Caribou, whose real name is Dan Snaith, earned the honour in 2008 for his album Andorra.

Other past winners have included Montreal's Patrick Watson (in 2007 for Close to Paradise) and Toronto hardcore punk band F--ked Up (2009's winner for The Chemistry of Common Life).

All 10 Polaris finalists will be celebrated in Toronto on Sept. 20 at a concert and gala, which will end with the announcement of this year's winner. The gala will be broadcast live on SIRIUS satellite radio and CBC Radio 3, and webcast live on Muchmusic.com.

MuchMusic will also broadcast the gala on TV later, on Sept. 25.

Twin musicians Tegan, left, and Sara have landed on the Polaris short list for the first time for their album Sainthood. (Mark Humphrey/Associated Press)