Guitarist Dave Keuning wrote the music for "Mr. Brightside" before meeting co-writer and lyricist Brandon Flowers. The Killers 2001 demo of "Mr. Brightside" (Brandon Flowers - Dave Keuning) was simply given free to those attending their 2002 appearances.

"Mr. Brightside" was the first single released by The Killers (lead vocalist Brandon Flowers, Dave Keuning, Mark Stoermer and Ronnie Vannucci Jr.) from their 2004 debut top ten Grammy nominated album "Hot Fuss". The single was issued in 2003 then re-released the next year as a multi-million selling tune peaking at number ten on Billboard, number three Adult and number four Dance.