The avant garde pop star was in a large bottle -- a replica of her "Fame" fragrance -- appearing in the transparent glass where attendees took photos and watched the singer get a tattoo on her neck.
The entertainer entered the the Solomon R. Guggenheim Museum on New York's Upper East Side Thursday night on top of a convertible. She posed for pictures and interacted with some fans.
Inside, she laid in the bottle in a sparkly top, black skirt and red wig. Then she took off some clothing and a wig -- now appearing in lingerie, including a thong -- and began receiving a tattoo of the back of her neck (she shaved the bottom half of the back of her head this week).
Gaga applied make-up and played on an iPad inside the bottle, where she was joined by four others. Edith Piaf played in background, as did David Bowie's "Fame" and various songs that featured Kanye West. She got her tattoo -- and danced in her seat -- as West's latest hit "Mercy" blasted in the background.
The masquerade black tie event featured a few hundred people, mostly dressed with eye masks and headgear. Celebrity attendees included Yoko Ono, Marc Jacobs, Paris Hilton, Michael Strahan, Jason Wu and Lindsay Lohan, who arrived late for the event.
Gaga also debuted a short film for the fragrance in collaboration with director Steven Klein.
The Grammy-winning singer released her multiplatinum debut, "The Fame," in 2008. That was followed by the platinum-selling albums "The Fame EP" and last year's "Born This Way."