Twenty of Joseph Haydn's 104 symphonies are in C major, making it his second most-used key, second only to D major. Of the 134 symphonies mistakenly attributed to Haydn that H. C. Robbins Landon lists in his catalog, 33 are in C major, more than any other key. Before the invention of the valves, Haydn did not write trumpet and timpani parts in his symphonies, except those in C major. Landon writes that it wasn't "until 1774 that Haydn uses trumpets and timpani in a key other than C major. . . and then only sparingly. " Most of Haydn's symphonies in C major are labelled "festive" and are of a primarily celebratory mood. (See also List of symphonies in C major).