The avant garde pop star was in a large bottle - a replica of her "Fame" fragrance bottle - at New York's Solomon R. Guggenheim Museum, appearing in a transparent glass where attendees took photos of Gaga and watched her get a tattoo on her neck. 

The entertainer entered the museum Thursday night on top of a convertible, where she posed for pictures. 

Inside, she laid in the bottle in a sparkly top, skirt and red wig. 

Then she stripped her clothes - now appearing in lingerie, including a thong - and began receiving a tattoo (she shaved the bottom half of the back of her head this week). 

The masquerade black tie event featured a few hundred people, mostly dressed with eye masks and headgear.

(Copyright 2012 by The Associated Press. All Rights Reserved.)