They're rumoured to be working on a new musical together.
And on Friday, Australian singer Sia was spotted catching up with American actress Kate Hudson, 38.
Sia, 41, ditched her signature face-covering wig and was spotted cutting a relaxed figure on the day.
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Now we can Sia! Australian singer Sia (pictured) ditched her signature wig to meet up with Kate Hudson in Los Angeles on Friday, as they continued work on a rumoured musical together
Wearing an all-black ensemble, Sia looked toned and wore a longsleeve top and tights.
The Chandelier singer had her natural locks out and neatly straightened, with her hair being balayage in style, a change from her usual blonde look.
Sia appeared to be wearing minimal makeup, highlighting her natural Beauty.
Familiar face: Hollywood actress Kate Hudson (right) meanwhile, wore a colourful flowing skirt and a white singlet, appearing to go braless
How we usually see her! Sia pictured in her iconic wig at the Vanity Fair Oscar Party in February
Meanwhile, How to Lose a Guy in 10 Days star Kate wore a colourful flowing skirt and a white singlet.
She covered her blonde locks with a light blue head scarf and sunglasses, and was accompanied by a male friend.
The pair are rumoured to be working on a musical that Sia is