Recently we saw hereditary grandduke Guillaume play the guitar at the baptism of his nephew Liam:

And he is certainly not the only musical royal out there:
- Princess Christina of the Netherlands (Maria Christina; born 18 February 1947) (Initially called Marijke) is the youngest of four daughters born to Queen Juliana of the Netherlands and Prince Bernhard of Lippe-Biesterfeld. She had a considerable talent for music and made a career in it. Christina studied pedagogy at the University of Groningen (NL) since 1966. Later she decided to get acquainted outside the Netherlands. She first went to Canada where she followed a vocal education at a conservatory in Montreal. After that, Christina decided to give singles lessons to children in New York. Christina has acted as a singer at various events in the Dutch royal family: at the baptism of her niece Carolina de Bourbon de Parme (youngest daughter of Irene) and her own youngest son Nicolás Guillermo. But also at the weddings of her nephew Bernhard van Oranje Nassau (2nd son of Margriet) & Annette Sekreve and of her own (oldest) son Bernardo Guillermo & Eva Valdez. And Christina sang at the funeral of her parents.
In 1990, the princess gave her name to a foundation for young musicians and young people. The Edith Stein Concourse was named Princess Christina Concours. She is the honorary chairman of this foundation. Christina has recorded 2 CDs, In 2000 a Christmas album and in 2002
The me nobody knows, including a song with Dutch singer Rob de Nijs. The proceeds went to the Princess Christina Concours and the victims of the attacks on September 11, 2001.
- On her 40th birthday Queen Maxima (then princess) launched a musical initiative Kinderen maken Muziek (Children make music). The program aims to bring as many children in the Netherlans as possible into a musical instrument and make music together. Máxima has worked out the idea with the Orange Fund and the Cultural Participation Fund.
https://www.youtube.com/watch?v=hPGZ6BrFVQE (2012 event of Kinderen maken Muziek)
- Amalia, Alexia and Ariane, the 3 daughters of Maxima and WA, have according to their parents music lessons. Among others Amalia plays the violin.
https://www.youtube.com/watch?v=yXyAtz6vHXk (Amalia singing a Sinterklaas song)