nfluence of one composer or work on another is a potentially dangerous concept. All too often our striving for such a connection encourages assumptions to be drawn regarding not only the interrelationship between specific persons or pieces, but even of whole repertoires. This article draws attention to one such repertoire Mozart's earliest set of six piano sonatas, K. 279-84 in which a tradition of supposed influence (from the piano sonatas of Joseph Haydn) has been accepted in the Mozart literature without question despite the flimsiest of supporting evidence. In this case, the origin of what I hope to demonstrate is a assumption lies in over-reliance on the interpretation of stylistic similarity. In order to highlight this at the outset, I will begin with a piece of deliberate misinterpretation. Example 1 shows the beginning of the development sections of two piano sonatas, Haydn's Hob. XVI:21 (1773) and Mozart's K. 279 (1774-5), both in C major. Both composers commence their developments with a tonal shift from the dominant region (G) to a fermata on a chord of E (Haydn, bar 67 ; Mozart, bar 76), after which they each introduce a false reprise of the first subject. At first sight, this seems quite a plausible illustration of model (Haydn) and imitation (Mozart). Among the critical vocabulary for defining the quality of influence, that is, the degree of relatedness between two works, one technique that has recently found favour with musicologists is that termed the 'Revisionary Ratio', a concept originally introduced some twenty years ago in the study of poetry by the distinguised literary theorist, Harold Bloom. Might Mozart have reacted in K. 279 to Haydn's finale according to one of Bloom's 'revisionary ratios', specifically the first ratio, 'clinamen' ?2 According to this theory, Mozart would have been so seized by