If I could only impress on the soul of every friend of music, and on high personages in particular, how inimitable are Mozart's works, how profound, how musically intelligent, how extraordinarily sensitive! (for this is how I understand them, how I feel them) — why then the nations would vie with each other to possess such a jewel within their frontiers. Prague should hold him fast — but should reward him, too: for without this, the history of great geniuses is sad indeed, and gives but little encouragement to posterity to further exertions; and unfortunately this is why so many promising intellects fall by the wayside.
Letter to Franz Rott (December 1787), from The collected correspondence, and London notebooks of Joseph Haydn, ed. H.C. Robbins Landon (1959), p. 73
Dear Haydn, how I love you! But other pianists? They're rather lukewarm towards you. Which is a great shame.
Sviatoslav Richter, quoted in Sviatoslav Richter: Notebooks and Conversations (2002) by Bruno Monsaingeon
Haydn is, together with Schumann, probably the most neglected and misunderstood of the greatest composers. Some might argue with this statement by saying that Haydn's works are frequently performed and that he has long been recognised as the father figure of Viennese Classicism. Papa Haydn has become one of the worst clichés in classical music. It degrades one of history's most innovative composers into a lovable but minor figure.
András Schiff, liner notes to Joseph Haydn Piano Sonatas, Teldec 0630-17141-2 (1997)