<p><br /> The Prince of Wales and the Duchess of Cornwall came across an unusual performance of the song Somewhere Over The Rainbow earlier.<br /> </p><p><br /> It was staged by sound sculptor Henry Dagg on his ''cat organ'' which consisted of a row of 16 squeaky toy cats<br /> </p><p><br /> The performance had the Royal couple reduced to tears of laughter.<br /> </p><p><br /> TV gardener Alan Titchmarsh, actor Brian Blessed and musician Jools Holland were among the celebrities at the new green festival in the grounds of Clarence House, the prince's official residence.<br /> </p>
