The youngest child of Prince William and Duchess Kate is reaching more milestones. As he is approaching his second birthday in April, Prince Louis has been revealed to start developing taste in music.

During a reception at Buckingham Palace to celebrate the 25th anniversary of youth mental health charity Place2Be on Monday, Duchess Kate told student choir teams from New North Academy and Salisbury Primary School of her youngest son’s favourite tune.

The students collaborated with the Royal Philharmonic Orchestra to perform an original song for the Duchess as part of the event.

“You’ve written it especially for tonight?” the 38-year-old said of the song. “Thank you so much! What a treat for me.”

After it was revealed that two of the choir members were having their birthday, the Duchess joked that it ought to be her singing to them instead.

She went on to share that the classic song Happy Birthday is “one of Louis’s favourite songs” and added that the young prince was “tucked up in bed” and therefore absent from the event.

The Duchess of Cambridge has been a royal patron of the organisation since 2013.

“Place2Be was one of the first charities I became patron of,” she said in a speech at the event.

“I knew it was special then, but having spent many years since, learning about the importance of childhood development, I see even more the value in the work that you do and I am hugely grateful for all that you have taught me over the past seven years.

“You taught me the importance of creating safe and nurturing environments within schools, embracing a holistic view of emotional well-being which permeates through the whole school system. You also taught me that it’s the simplest things that make a difference to children. It’s the quality time that is spent with them. It’s the time you take to listen to them.”

This article originally appeared on Over60.