Sia's Face Accidentally Revealed During Windy Concert

— -- Sia never shows her face onstage. Or almost never: Fans finally caught a glimpse of the singer's elusive features during a Wednesday performance in Colorado.

During the opening night at SeriesFest, at Red Rocks Amphitheatre in Morrison, the Grammy Award winner's signature blond wig was blown by the wind, revealing her face to the crowd.

Sia, 40, explained why she doesn't show her face onstage or in interviews.

"I don't want to be famous or recognizable," she told ABC News' Chris Connelly in 2014. "I don't want to be critiqued about the way that I look on the internet. I've been writing pop songs for pop stars for a couple years and see what their lives are like, and that's just not something I want."