When under six years of age, Mozart surprised his father, though well accustomed to these premature manifestations of musical genius, by the production of a concerto for the harpsichord, written in every respect according to rule, the only objection to which was its difficulty of execution. This circumstance at once determined Leopold Mozart to let the youthful prodigy be seen at some of the courts of Germany. He therefore carried his whole family, as soon as Wolfgang had completed his sixth year, to Munich, where they were received by the Elector in so flattering a manner, that the party returned to Salzburg to prepare for other visits. In 1762 they proceeded to Vienna, and performed at court. Here Mozart, when sitting down to play, said to the emperor Francis I.,—“Is not M. Wagenseil here? he ought to be present; he understands such matters.” The emperor sent for M. Wagenseil. “Sir,” said the child to the composer, “I shall play one of your concertos,—you must turn the leaves for me.” About the same time, a small violin was purchased for him, merely for his amusement; but while it was supposed to be little more than a toy in his hands, he made himself so far a master of the instrument, that when Wenzl, the violinist, brought his newly composed trios to Leopold Mozart for his opinion, Wolfgang supplicated to be allowed to take the second violin part, and accomplished the task as much to the satisfaction of the composer as to the wonder of all. In 1763 the Mozart family commenced an extended tour, giving concerts in the principal cities through which they passed. In Paris they continued five months, and Wolfgang performed on the organ in the _chapelle du roi_, in presence of the whole court. There he composed and published his first two works, which, compared with other productions of the day, are by no means trivial. In April, 1764, the party arrived in London, where they remained till the middle of the following year. Here, as in France, the boy exhibited his talents before the royal family, and underwent more severe trials than any to which he had before been exposed, through which he passed in a most triumphant manner. So much interest did he excite in London, that the Hon. Daines Barrington drew up an account of his extraordinary performances, which was read before the Royal Society, and declared by the council of that body to be sufficiently interesting and important to form part of the Philosophical Transactions, in the seventieth volume of which it is published. But some suspicions having been entertained by many persons that the declared was not the real age of the youthful prodigy, Mr. Barrington obtained, through Count Haslang, then Bavarian minister at the British court, a certificate of Wolfgang’s birth, signed by the chaplain of the Archbishop of Salzburg, which at once dispelled all doubts on the subject.