Irish songwriter Brendan Graham has been chosen to write the lyrics for the song dedicated to the new royal child. Prince William and his wife Kate Middleton are currently expecting their first baby together, which is due in July.

In what is an extraordinary recognition of his writing talent, Tipperary-born Graham – best known for penning the lyrics to the phenomenally successful 'You Raise Me Up' – was chosen ahead of any number of other leading international writers, who might otherwise have been selected to pen the lyrics. The song 'Sleep On' – a lullaby, dedicated to minimising the number of sleepless nights that lie ahead for the new parents! – is being sung by Hayley Westerna.

''I was contacted by producer Jon Cohen asking if I would be interested in listening to a melody with a view to putting a lyric to it," Brendan Graham told Hot Press. "I had worked with Jon previously who is a good and talented man. Initially, I was told little about the project – but, when the melody arrived, I really liked its beauty of innocence. It had a certain soothing quality so I said 'yes'. Then, was it revealed that it had to be a lullaby theme – and that it was royal wedding composer, Paul Mealor's way of saying 'thank you' to Prince William and Kate and of welcoming their new baby into the world."

Welsh composer, Mealor had previously been commissioned to write the widely-acclaimed 'Ubi Caritas' for the wedding of Prince William and Kate Middleton.

''It was an honour to be asked and a pleasure to be involved with something that would have even a small connection with such a joyous occasion,'' Brendan added.

As is often the case for writers, the song lyrics had to be delivered to a deadline.

''They needed the lyric by that weekend," Graham explained, "so the family holiday I was on went by the wayside. Thankfully, both composer and singer liked the lyric – and Hayley Westenra's interpretation is everything I could have wished for – intimate and tender but with a slight vulnerability. She brings you right in there, beside the cradle.

"'While mindful of to whom the song was dedicated," he added, "it was also important that the 'story' of the song would be open for any parent to identify with – and be something which any parent could sing to a child'."

The song is being given its world premiere on Classic FM in the UK today. Westerna has recorded an album of existing lullabies, called Hushabye, which will be released in June. Mealor and Graham's 'Sleep On' is the only original piece, especially composed for the album.

''It is a real league of nations collaboration," songwriter and novelist Graham reflected. "Hayley is a New Zealander, Paul is Welsh, producer Jon Cohen is South African – and so it's wonderful to be able to bring a contribution from Ireland to it.''

In addition to his contribution to the wedding ceremony, Mealor is best known for penning 'Wherever You Are', which was a huge-selling No. 1 hit for for Gareth Malone's Military Wives Choir.

Brendan Graham is among Ireland's most successful songwriters ever, with two Eurovision winners to his credit, as well as hit songs recorded by a string of major Irish and international artists. 'You Raise Me Up', the music for which is by Rolf Lovland, is one of the most widely covered songs in popular music history, with almost 700 versions by different artistes already to its credit, and total sales approaching the 100 million unit mark.

In March of this year, on Washington's Capitol Hill, Graham's song 'O, America!', written with American composer, William Joseph and performed by tenor, Anthony Kearns, received a standing ovation, led by US President, Barack Obama, himself.