"'BLIND TOM.'--This extraordinary musical prodigy gave two performances in Dundee yesterday, and on each occasion the powers displayed by him were so marvellous as to verge upon the miraculous. Our readers must not suppose that his proficiency is merely of an ordinary kind, or that his notoriety is another species of Barnumism. The letter we published yesterday from a private friend, in whose opinions we place the greatest confidence, shows that it is not so; and we believe the opinions of all who yesterday heard him will be found to be those of astonishment and admiration. History affords no parallel to 'Blind Tom.' His ability would be marvellous, even if he had his eyesight; but, as we have before remarked, when it is considered that he is blind, it is beyond measure strange. Unless one sees or hears him play, he is unable properly to understand the extent of his ability. Test him how you may, he never fails. His memory is as miraculous as his musical powers; and he plays over a piece he has never heard before with almost infallible exactitude. Yesterday several gentlemen went to the platform, and played over pieces; and, during the time they were so occupied, it was amusing to witness Tom's contortions of his body, and his movements generally. He swayed himself about, his eyeballs rolled, his fingers twitched involuntarily, and he seemed like one possessed; and, on being allowed to seat himself at the piano, he repeated from memory the various pieces which had been played to him. In the evening, Mr. Hirst played over a number of pieces of the most difficult character, all of which Tom produced with fidelity. "On inquiry, we find that his proficiency is a natural gift. From his earliest infancy he betrayed the utmost interest in musical sounds of every kind,--the cries of animals, the moaning of the wind, the rushing of waters, and the like; and when he was allowed to go out in the fields, if he heard a bird sing, he rushed off towards it with frantic delight. We publish a letter we received the other day from an intimate friend in another town,--a gentleman of great musical taste, and no little executive ability,--who is well qualified to give an opinion on such matters. He says,--