In 1799 Haydn was probably the most famous and successful composer who had ever lived, for his career coincided with the beginnings of a mass market for music; he was the first musician whose fame was created by the dissemination of his music in printed copies. Printed editions had enhanced the international reputations of Corelli and Handel, but they, like other Baroque composers, established themselves in the firs t instance through their personal appearances as virtuoso performers. Haydn was not an outstanding virtuoso on any instrument (except for that collective instrument, the orchestra), and until his long-standing patron Prince Nikolaus Esterházy died in 1790 he was not free to live the life of a travelling celebrity. Before the 1790s Haydn's fame also depended to an unusual degree on his cultivation of a limited number of genres of instrumental music — the symphony, the piano trio, the keyboard sonata and, above all, the string quartet — though in the course of a busy career he had composed in virtually every genre of the time. H C Robbins Landon has suggested in his monumental biography of Haydn that in the 1780s the composer began to avoid certain genres out of a desire to avoid direct competition with his friend Mozart: he stopped writing operas (with the exception of one commissioned work) and keyboard concertos altogether after Mozart's mature works in these genres appeared in the course of the 1780s.