Now you Sia ... now you don't.
The singer -- known for covering her face onstage -- ditched her wig and showed her mug as she mingled with producer Zach Shields outside the "Ozark" Netflix party Tuesday night at APL Restaurant on the Hollywood Walk of Fame.
But, it was back to business as usual when Sia approached our camera before and after the party ... covering her face with both hands.
Sia gave a nod to Aretha Franklin, who is gravely ill from cancer ... and told us her favorite song by the Queen of Soul.