He subsequently visited Vienna before taking a post as Kapellmeister to Duke Karl Eugen of Württemberg in Stuttgart in 1753. This period saw some of his greatest successes, including the composition of what are regarded as some of his best works. Many were staged at the Duke's private theatres in the Palace of Ludwigsburg, outside Stuttgart. Mozart and his father Leopold passed through Ludwigsburg in 1763 on their "grand tour" and met the composer. Jommelli returned to Naples in 1768, by which time "opera buffa" was more popular than Jommelli's "opera seria", and his last works were not so well received. He suffered a stroke in 1771 which partially paralysed him, but continued to work until his death three years later, in Naples. Jommelli wrote cantatas, oratorios and other sacred works, but by far the most important part of his output were his operas, particularly his "opere serie" of which he composed around sixty, several with libretti by Metastasio. These tended to concentrate more on the story and drama of the opera than on flashy technical displays by the singers, as was the norm in Italian opera at that time. He wrote more ensemble numbers and choruses, and, influenced by French opera composers such as Jean-Philippe Rameau, introduced ballets into his work. He used the orchestra (particularly the wind instruments) in a much more prominent way to depict what was going on in the story, including passages for orchestra alone, rather than consigning it to merely support for the singers. From Hasse, he learned to write orchestrally accompanied recitatives rather than just "secco" recitatives for voice and continuo (mainly harpsichord). His reforms are sometimes regarded as equal in importance to Christoph Willibald Gluck's.