Lady Gaga surprised her musical partner Tony Bennett when they were performing in Washington Saturday with a birthday serenade and an enormous cake. It was the final concert of their sold-out, seven-month concert tour “Cheek To Cheek.”

Bennett turned 89 Monday, and Mother Monster wanted to do something special for him, People reported. During the final moments of the duo’s last show at the Kennedy Center in Washington, Gaga, 29, led the entire audience in singing “Happy Birthday” to the 18-time Grammy Award winner. The audience was on its feet. Earlier, Gaga sang Duke Ellington’s “I’m Beginning To See The Light” to a beaming Bennett as the audience cheered.

Before the show, she shared her surprise on Instagram. The singer took to the photo sharing app for a close up of the multitiered sugar confection’s minute detailing. Edible versions of both singers and their pets topped the white masterpiece. 

“Look at the details on this cake. @missasiakinney and Happy made it too!” the pop star wrote. The cake was created by Charm City Cakes’s  Duff Goldman of Food Network fame. It is based on the cake originally created for President John F. Kennedy’s birthday at which  Marilyn Monroe famously sang “Happy Birthday Mr. President.”

Gaga also retweeted a video captured by a fan of the birthday performance to her millions of Twitter followers. The Saturday concert marked the end of the Gaga and Bennett’s lengthy tour, which took them to Spain, Italy, Denmark and Monaco, among other places. 

The pair still has one last “Cheek to Cheek”  moment to look forward to. They just received an Emmy nomination for Outstanding Variety Special for their PBS special. This marks the duo’s second major nomination after winning a Grammy earlier this year for Best Traditional Pop Vocal Album for their 1 million selling jazz record.