Singer Tori Amos has failed to win over London's tough theatre critics with her new musical The Light Princess after premiering the show on Wednesday (09Oct13), 18 months after its originally scheduled debut.

The Professional Widow star spent more than five years working on the stage show, an adaptation of George MACDonald's 19th century fairytale, but its initial April, 2012 launch was scrapped and the project was postponed indefinitely.

The musical, about a girl who loses her mother and grows so light with grief she begins to float, was back on track a year ago, and Amos and her co-writer, playwright Samuel Adamson, unveiled the long-awaited musical at the National Theatre on Wednesday.

However, the finished product, directed by Marianne Elliott, isn't a big hit with critics - Simon Edge of the Daily Express singles out lead actress Rosalie Craig for a "staggeringly good performance", but the Daily Telegraph's Charles Spencer claims the songs let down the production, writing, "You feel you are being preached at. The songs...feature a lot of wailing vocals and only very occasionally run to a decent tune or a witty lyric. The orchestrations for woodwind, strings and piano seem fussy and I can't say that any of the numbers lodged in my memory on first hearing."

Time Out writer Andrzej Lukowski is not quite as harsh in his review - he brands the show a "visual and technical tour de force", and lavishes praise on Craig for a performance that will "blow your mind and melt your heart", but he isn't too impressed with the score, admitting it "doesn't really do the business in the tunes department".