"We concur in everything that has been said by our musical reporter, describing her extraordinary genius--her unrivalled combination of power and art. Nothing has been exaggerated, not an iota. Three years ago, more or less, we heard Jenny Lind on many occasions, when she made the first great sensation in Europe, by her debut at the London Opera House. Then she was great in power--in art--in genius; now she is greater in all. We speak from experience and conviction. Then she astonished, and pleased, and fascinated the thousands of the British aristocracy; now she will fascinate, and please, and delight, and almost make mad with musical excitement, the millions of the American democracy. To-morrow night, this new sensation--this fresh movement--this excitement excelling all former excitements--will be called into existence, when she pours out the notes of Casta Diva, and exhibits her astonishing powers--her wonderful peculiarities, that seem more of heaven than of earth--more of a voice from eternity, than from the lips of a human being. "We speak soberly--seriously--calmly. The public expectation has run very high for the last week--higher than at any former period of our past musical annals. But high as it has risen, the reality--the fact--the concert--the voice of Jenny Lind--will far surpass all past expectations. Jenny Lind is a wonder, and a prodigy in song--and no mistake." Barnum had not hoped to manage such an enormous enterprise as this one, without some trouble and anxiety, but he soon discovered that in this case, realization far exceeded anticipation. He often declared that from the first concert, September 11th, 1850, until the ninety-third concert, June 9th, 1851, he did not experience a single waking moment that was free from care. Miss Lind was utterly unprepared for the enthusiasm of her American audience, and it is scarcely to be wondered at that she should appear to listen at first to the dishonorable counsels of some of her friends, who constantly besought her to break her contract with Barnum, who, they urged, was "coining money out of her genius," and to take the enterprise into her own hands. But whether Miss Lind realized that Mr. Barnum's management was largely responsible for her triumph, or whether she was simply too high-minded to consider such a breach of honor, certain it is that she continued to stand by her contract. John Jay, her lawyer, took every occasion to interfere, and Barnum suffered much from his unreasonable intrusions. The following letter, written to Mr. Joshua Bates of Baring Bros. & Co., London, will show the difficulties which beset the perplexed manager: "NEW YORK, October 23, 1850. "JOSHUA BATES, Esq.: