Leonard Cohen’s iconic song “Hallelujah” has been covered by numerous artists, ranging from The Velvet Underground’s John Cale to Canadian singer-songerwiter Rufus Wainwright, who managed to top his immensely memorable rendition of the song in truly epic style by enlisting the voices of a 1,500-member choir to join him.

According to Toronto Life, Wainwright and the leaders of Toronto-based Choir! Choir! Choir! hatched a plan to assemble the epic choral group in Toronto’s Hearn Generating Station, a decommissioned electrical generating station, to accompany him in this once-in-a-lifetime performance.

Related: Rufus Wainwright Debuts Opera, Performs Symphonic Versions Of ‘April Fools’, ‘Vibrate’ At Montreal Jazz Fest

Among the singers assembled for the performance, notes Toronto Life, was none other than former Governor General Adrienne Clarkson. Watch: