Her fans were teased earlier this week with the possibility of a surprise set at England's Glastonbury Festival.
But Lady Gaga, 33, lured her famous fans out for a special performance Monday night at Harlem's historic Apollo Theater in New York City.
Leading the parade of famous figures were longtime couple Michael Douglas, 74, and Catherine Zeta-Jones, 49, as well as Neil Patrick Harris, 46, and his husband David Burtka, 44.
Star power: Michael Douglas, 74, and Catherine Zeta-Jones, 49, led the stars ahead of Lady Gaga's performance at Harlem's historic Apollo Theater on Monday
Gaga was seen earlier in the day in an all-black ensemble, and Michael seems to have matched her with his black shirt and matching trousers.
Catherine brought enough color for the two of them with a striking red, black and white dress.
The nearly floor-length outfit featured abstract butterfly-like designs and featured a plunging top to highlight her cleavage.
The Traffic star paired the outfit with a set of black open-toe heels and wore a thin black ribbon around her neck.
She carried a small black clutch and had her raven tresses pulled back in a ponytail.
Back in black: As her high-profile fans arrived at the theater, Lady Gaga was seen entering the venue in a striking black leather outfit
Revealing: The look featured an edgy black bandeau tied together with multiple long strings
Showing some skin: She paired her top with a high-waisted black leather skirt and black gloves that extended beyond her elbows and had her name printed at the top
As her high-profile fans arrived at the theater, Lady Gaga was seen entering the venue in a striking black leather outfit.
The look featured an edgy black bandeau tied together with multiple long strings.
The skimpy look highlighted her trim tummy and bared her shoulders.
She paired her top with a high-waisted black leather skirt and black gloves that extended beyond her elbows.
The peroxide blonde singer and actress toted a black handbag as she prepared for the performance.
Matching couple: Neil Patrick Harris showed off a new mustache and a bowler hat, while his husband David Burtka wore a fierce leopard print shirt and a white jacket
Colorful display: The couple were joined by drag queen William, who flaunted her figure in a two-piece outfit covered in multicolored Keith Haring designs
Also among those excited to see the Born This Way singer perform were Neil Patrick Harris and his husband David Burtka.
The How I Met Your Mother star went with a simple black short-sleeve shirt and charcoal jeans, but he spiced up the look with a black bowler hat, black flower print shoes, and a new mustache.
David looked fierce in a leopard print shirt, which he paired with a white jacket and black jeans.
The couple were joined by drag queen William, who flaunted her figure in a two-piece outfit covered in multicolored Keith Haring designs.
Food God Jonathan Cheban arrived in a simple gray-blue T-shirt, which he jazzed up with a diamond encrusted necklace, bracelets and a luxury wrist watch.
No fuss: Food God Jonathan Cheban arrived in a simple gray-blue T-shirt, which he jazzed up with a diamond encrusted necklace, bracelets and a luxury wrist watch
Flower power: Saturday Night Live star Heidi Gardner was a vision of spring in her pastel floral skirt and matching hair bow. Beth Ostrosky Stern, an actress and the wife of radio legend Howard Stern, showed off her lovely long blonde locks over a spotted print gown and a white Gucci handbag.
Rocker chic: The Sopranos actor and E Street Band stalwart Steven Van Zandt had on his trademark bandana and a colorful multi-patterned shirt, while his wife Maureen Van
