THE BLACK SWAN AT THE ATHENEUM. – A small and decidedly mixed audience assembled at the Atheneum last evening, on the occasion of a concert given by four colored artists, the principal one being the Black Swan, (Miss E. T. Greenfield,) who gained a reputation as a concert singer some years since. Had the management been good, and the public had due notice of the concert, no doubt the house would have been filled; as it was the proceeds, which were to benefit the Union Congregational Church, could not have been more than enough to pay expenses. The Swan is blessed with two voices. Her soprano voice is quite good and distinct, and her bariton voice exceeds in quality that of some gentlemen who profess to be baritone singers. When she changed her voice, it excited the risibilities of several youthful individuals of color in the gallery, and it may here be remarked that these youngsters were noisy throughout the entertainment, during which a continual whispering and laughing was kept up. The Swan presided at the piano in an able manner, and all the heavy part of the concert was put on her broad shoulders. The piano, a small second-hand affair which had evidently seen service, was enough to spoil any singing. Miss Kate Lanier was well received and loudly applauded. She has a naturally sweet soprano voice, and with culture, she bids fair to be successful as a concert singer; if possessed of a shade lighter complexion no doubt she would attain a good position in the vocal world. Possessors of poorer voices than hers who had the good or bad fortune to have light complexions, have received the applause of crowded houses, and even figured upon the Opera boards. Her personal appearance is exceedingly good, and she carries herself in a lady-like manner. Miss Rachel Alexander, seemed somewhat embarrassed, and did not give expression enough to her singing to allow of any judgment being passed upon it, although she promises well. Mr. James J. Spelman was acceptable in the songs he gave. As a manager, Mr. Spelman did not do well. To be successful he should have made the fact that the concert was to take place generally known, procured a good piano, and some one to play it, instead of leaving the accompaniments, to his principal artiste. Miss Lanier attempted two piano solos, but the instrument alone would have made them appear just what they were – ridiculous.