Signor Costa's "Don Carlos" was produced for the eminent conductor's own benefit, on the 20th June. It had been long talked of, long expected, and the musical dilettanti of the day were naturally excited by curiosity as to the result of its production. The "Malek Adel" of the same composer, although when it was brought out it attained a certain kind of celebrity (chiefly from the renown of a cavatina sung by Rubini), and was even repeated upon the Italian stage in Paris, had long since disappeared from the boards. Nevertheless considerable expectations were still afloat. "Don Carlos" was well "mounted," and supported by Grisi, Mario, Lablache, and Fornasari. Like its predecessor, it utterly failed to maintain any prominence. It survived but a very few nights, and then, like "Malek Adel," sank into the vast "limbo" of forgotten works. Whatever may have been the real merit of this production, from a managerial point of view it was undeniably a failure. That is to say, it neither attracted the public nor brought money to the treasury. It is by such tests alone that an operatic or a theatrical director can discover what is and is not conducive to the interest of an establishment. The subject of "Don Carlos," it may be stated, was "sombre" and lugubrious, and on the first night, Mario and Lablache were both hoarse, wearied by long rehearsals. This could not be otherwise than detrimental to "first impressions," but the artists gallantly supported their conductor's fame on the second night of performance.