05/04/2013 at 12:00 PM EDT
isn't exactly known for being quiet.
But on Wednesday, the singer had a low-key evening with two female friends at the Chateau Marmont in West Hollywood.
With two tables full of bodyguards sitting behind her, Gaga looked "quite tired and somber" throughout the evening, an onlooker tells PEOPLE. "She was talking low and leaning into her friends. She didn't laugh or smile the entire time, just straight-faced chatting and sipping on some wine."
Sporting thick, blonde dreadlocks the "Born This Way" singer and her friends were "so quiet you never would have noticed they were there if it weren't for the bodyguards," the source adds.