Like the great huckster P.T. Barnum, the folks at Cirque du Soleil know how to elicit the sort of oohs and aahs that come only with, well, the greatest show on earth. They proved this once again this past spring when they pitched their grand white tent downtown for a long run of Alegría. From the opening clown who delighted both children and grown-ups by flinging popcorn at the audience from a box as big as a man, to the aerial high bar act that featured muscled madmen flinging themselves through the air on a swinging silver trapeze, the show was a wonderland of amazements. But what truly set the Canadian circus apart were the gorgeous New Age tunes sung by Eve Monpetit and Nathalie Noël. The soundtrack was nominated for a Grammy in 1996. Even Barnum can't top that.