As Scott Burnham has recently noted, it is a common practice for musical analysts to ignore various facts about a piece, its origin, its reception history, and so forth, and instead focus on "the music itself" (Burnham 1996). And in many respects and contexts this is all well and good, for as Burnham has also noted, this practice is predicated on the fact that there are musical grammars which are manifest through "palpable, internalized prototypes" (13). On the other hand, there are cases when contextual information about a piece is needed in order to make sense of our analytical efforts. To put it another way, while we may not need such information in our gathering of various facts "from the music itself," we may well need to take things such as genre, performance practice, and historical context into account when interpreting those facts. And since the processes of gathering and interpreting analytical data are tightly intertwined and mutually influential, the need to take such contextual information into account may be all the more pressing in those instances where we do not find what we expect. In this paper we present such a case: Chopin's familiar Prelude in E minor, op. 28, no. 4. Though a staple of basic piano and theory peda-