During this year Napoleon held his celebrated congress of princes at Erfurt. Spohr was consumed by a burning desire to behold Napoleon and the surrounding princes, and went to Erfurt. Here he found that a French theatrical troupe was performing every evening before the august assembly, but only the privileged few could by any possibility gain admittance to the theatre. Spohr's ingenuity was equal to the emergency, and making friends with the second horn player, he induced that artist to allow him to substitute for him one night. Spohr had never in his life attempted to play the horn, but it was now necessary for him to acquire the art before night, and he set to work with such vim that by the time of the performance his lips were swollen and black, but he was able to produce the requisite tones. The orchestra having received strict injunctions to sit with their backs to the brilliant assembly, probably to protect their eyesight from its dazzling effects, Spohr fitted himself out with a small mirror, and placing this upon his music-rack, he was able to enjoy for a couple of hours the vision of the great Napoleon, who, with his most distinguished guests, occupied the front row of the stalls. Spohr remained at Gotha until 1813, when he was offered and accepted the post of the leadership at the Theatre an der Wien at Vienna, and while here he composed his opera of "Faust," which, however, was not produced at that time. He also wrote a cantata in celebration of the battle of Leipzig, which he did not succeed in producing, and not feeling satisfied with his position, and having various disagreements with the management, the engagement was cancelled by mutual consent. During his stay in Vienna Spohr was frequently in contact with Beethoven, and though he admired that great master he criticised some of his compositions very severely, and is said to have remarked that "Beethoven was wanting in aesthetic culture and sense of beauty," a remark difficult to understand in these later days. It is the more incomprehensible from the fact that Spohr in after years was the very first musician of eminence to interest himself in Wagner's talent, for he brought out at Cassel "Der Fliegende Hollaender," and continued with "Tannhaeuser," notwithstanding the opposition of the court. He considered Wagner to be by far the greatest of all dramatic composers living at that time. In 1815 he made a concert tour in France and Italy, during which he met Rossini and Paganini, playing at Venice a sinfonia concertante of his own composition, with the latter.