From 1790, he conducted both royal theater orchestras. He was highly respected by Mozart, Haydn and Beethoven; the latter two preferred him as conductor of their new works (e.g., Beethoven's First Symphony in 1800). Wranitzky was a prolific composer. His output comprises ten operas, 44 symphonies, at least 56 string quartets (some sources give a number as high as 73) and a large amount of other orchestral and chamber music. His opera, "Oberon – The Fairy King" from 1789 was a favorite in this genre and inspired Emanuel Schikaneder to write the libretto of "The Magic Flute" for Mozart in 1791; in the mid-1790s, Goethe sought to collaborate with Wranitzky on a sequel to the Mozart opera. Today, Wranitzky is identified as being one of three possible composers said to have composed the Austrian national anthem (the identity of the actual composer is not definitively known).