Prince William and wife Kate's baby might be due in July, but a lullaby penned by a composer, whose work was chosen for their wedding, already awaits the future monarch of Britain.
Paul Mealor said he has written Sleep On because it seemed a natural progression to accompany their next stage of married life.
The song is sung by classical star Hayley Westenra, who has included it on a new album of lullabies that has been sent to the couple to help them through any sleepless nights with their new arrival, due in July.
She has dedicated the album to the Royal baby, The Telegraph reported.
Mealor's Ubi Caritas, his most famous work, which was chosen for the Royal Wedding, was regarded as one of the musical highlights.
It is not known why the Duke and Duchess of Cambridge chose the little-known Welsh composer but it is believed that Ubi caritas, which premiered last Autumn at St Andrew's University, where the royal couple met, held some sway. He also hails from Anglesey, where they currently reside.
The 37-year-old, who also wrote the chart-topping Wherever You Are for the Military Wives choir, said: "After writing music for the Royal Wedding it seemed natural to provide the musical accompaniment for the next stage of the royal couple's journey together."
Westenra's new album, called Hushabye, is designed to calm parents and children alike with calming tunes such as Hushabye Mountain and Twinkle Twinkle Little Star and is released in June.
Westenra, who has performed for the Prince of Wales, said: "Paul and I got together to work on a song called 'Sleep On' in honour of William and Kate's new arrival as it's such a joyous occasion which we can all celebrate."