It was a moving tribute to local man Ger 'Farmer' Foley, whose funeral had been that day. Ger died, aged 45, from complications from Cystic Fibrosis, leaving behind his wife and two children.
Speaking to the Anton Savage Show this morning, Brian O'Sullivan said the song had special meaning to them as they had sung it together every New Year's Eve.
Ger, who was a sound engineer and massive music fan, received a double lung transplant 12 years ago which Brian says gave him "a new lease of life" and the opportunity to have his two children.
Brian also urged people to carry a donor card, saying he hoped that the video's success would lead to a greater awareness of their importance.
And the video has gone viral, being shared widely all over the world.
Just when you thought the Irish people couldn't be any more delightful... A wake at a pub somewhere near Kerry... https://t.co/L5Tx9DfsmT— Greg Winter (@Greg_Winter) March 29, 2016
Yo quiero un funeral así! "The Killers: Mr Brightside sing-a-long at County Kerry wake goes viral" https://t.co/mulkA8dXCH— Mario Zúñiga 😷 (@MZunigaP) March 29, 2016
Even the Killers themselves took notice, saying: "May we all have friends like this".