Sia Celebrates Her 40th Birthday | InStyle.com 

And another star joins the 40 club! This time it\'s Australian singer/songwriter, Sia, who is celebrating her 40th birthday today.

Sia may have recently topped the music charts with her powerful single "Chandelier" and the songs that followed—including "Elastic Heart," "Big Girls Cry" and "Alive"—from her most recent album, but it so happens that 

is actually her sixth studio record! Sia started her career in the mid-1990s with the band, Crisp and after they disbanded, she embarked on her own musical career in the U.K., and ultimately the States.

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was released in 2004 and included the commercial hit, "Breathe Me," which began to earn traction in the U.S. in 2005 after it was featured in the final episode of HBO\'s

. The now 40-year-old continued to release music and even co-wrote hits for singers including Christina Aguilera, Britney Spears, Alicia Keys, Beyoncé and Rihanna.

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, Sia is already hard at work with her seventh album,

, which is due out January 29. Until then, celebrate the singer/songwriter\'s 40th birthday with her most powerful music videos to date:

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