The Formal Plan of Each of the Purgatory Sonatas
By Christopher Fulkerson
Each of the Purgatory Sonatas has the same pattern of speeds and recurrances in four strata. The arithmetic here is probably that of La turba che rimasle li.
It may be noticed that I write that the graph below is of the plan "probably" used for this piece. I often make a plan for a projected piece that has a title, and then, when working with the plan, I all too often discover that it's going to have to involve a different ensemble than the one I originally planned. By the time I am working in score, the piece has existed in several versions, for example, a simple line drawing; then a line drawing on graph paper; next a metrical plan; finally a score. Not infrequently each of these stages involves more than one version. At each stage I adapt the tempi and gruppetti and change these to suit the idea, often to try to make the piece easier to play. So while the proportions will definitely be those of the graph here, without careful study, I can't be sure which piece this arithmetic is used for. And rather than spend the time studying to figure out just which piece this graph represents, I'd prefer to spend my time writing a new piece.