Max McNown’s first international tour already has a royal seal of approval. The 23-year-old singer-songwriter shared a carousel of photos on Instagram from his show in Stockholm, Sweden, on March 11, and the first pic included a royal guest: Princess Madeleine! “ ‘Don’t panic, but we’ve been informed that Princess Madeleine of Sweden is on her way to watch your show.’ Those words were NOT on my 2025 Bingo card,” McNown shared in the caption. The royal, 42, was dressed casually in blue jeans and a black t-shirt, matching McNown’s vibes as he grinned in jeans, a henley and a backward hat. “I still can’t comprehend the fact that a crowd like this showed up to watch me play my own show in this beautiful country I’ve never even been to before,” he added in his caption. “Last night was unforgettable.” The “A Lot More Free” performer also shared some shots of him and his band on stage at the Fållan concert venue and walking the streets of the Johanneshov district of the Swedish capitol city. Princess Madeleine is the youngest child of King Carl XVI Gustaf — the longest-reigning monarch in Swedish history — and Queen Silvia. She is currently ninth in line to the throne behind her older sister, Crown Princess Victoria, her older brother, Prince Carl Philip, and their respective children. Madeleine married British-born American financier Christopher O'Neill on June 8, 2013. They share three children: Princess Leonore, 11, Prince Nicolas, 9, and Princess Adrienne, 7. Can't get enough of PEOPLE's Royals coverage? Sign up for our free Royals newsletter to get the latest updates. Last year, the princess and her family moved back to Sweden after living in Florida in recent years. When PEOPLE exclusively spoke with the Swedish royal at the World Childhood Foundation’s 25th Anniversary Gala in New York City on Nov. 14, she shared that the U.S. "will always remain close to my heart." "Returning to meet with colleagues and friends of Childhood USA is deeply meaningful to me," she added. "Having shared experiences and created memories during my time living in New York City and Miami, I always look forward to reconnecting with those who have been vital to supporting our mission."