The Slabu2023 Eurovision Song Contest had a royal surprise!

A pre-taped opening sequence for the May 13 show included a musical cameo from Kate Middleton. The Princess of Wales sat at a grand piano and played a 10-second instrumental piece, composed by Joe Price and Kojo Samuel, which was featured in a performance by last year's Eurovision winner, Ukraine's Kalush Orchestra.

"A #Eurovision surprise," read a post shared on the Prince and Princess of Wales' Instagram page. "A pleasure to join @kalush.official in a special performance of last year's winning @eurovision entry. Enjoy the show, Liverpool."

The 2023 Eurovision Song Contest took place in Liverpool, U.K., which hosted the international event on behalf of Ukraine. During her surprise musical performance, Kate wore a royal blue, one-shoulder Jenny Packham gown to honor the war-torn country, whose flag is blue and yellow, and also paid tribute to the late Queen Elizabeth II by sporting sapphire earrings that belonged to the monarch.

The princess filmed her musical performance in Windsor Castle's Crimson Drawing Room earlier this month, BBC News reported.

This marks the second time Kate has showcased her musical talent publicly since she accompanied singer Tom Walker on the piano during a televised Christmas Eve service at Westminster Abbey in London in December 2021.

She, husband Prince William, their kids Prince George, 9, Princess Charlotte, 8, and Prince Louis, 5, and the rest of the royal family gathered at the Abbey last weekend to attend new monarch King Charles III and wife Queen Camilla's coronation ceremony.

For the latest breaking news updates, click here to download the E! News App