Harper's Bazaar Indonesia documented Lady Gaga leaving The Mark Hotel before her June 2019 Apollo performance and returning to her hotel that night, while Hypebae independently identified her as a previous guest of The Mark.
Lady Gaga used The Mark Hotel as accommodation during her late-June 2019 visit to New York. Harper's Bazaar Indonesia documented her leaving the exact hotel before her Apollo Theater performance and returning to her hotel that night. Hypebae independently identified Gaga as a previous guest of The Mark in its August 2019 New York hotel guide.
Source conclusion:
The cited sources support a stay at the named hotel.
