Warren Darcy, in a review of William Caplin's Classical Form: A Theory of Formal Functions for the Instrumental Music of Haydn, Mozart, and Beethoven (New York: Oxford University Press, 1998), ‘hoped that future research into the subject of musical form [would] be less concerned with classifying compositional choices and more concerned with explicating the expressive purposes behind them’ (Music Theory Spectrum 22/1 (2000), 125). We can presume that Darcy hoped to provide such a hermeneutically sensitive theory of form in his and James Hepokoski's contribution to the subject, Elements of Sonata Theory: Norms, Types, and Deformations in the Late-Eighteenth-Century Sonata, the volume under review here. This substantial study sets its task as ‘uncovering and interpreting the dialogue of an individual piece with the background set of norms’ (11), a project that first involves assessing the compositional conventionality of an extensive array of musical processes within various musical parameters – from the rhetorical emphasis on a single point of arrival to the arrangement of thematic material across an entire sonata movement. Individual compositional decisions are considered either as adopting a stylistic ‘default’, a formal outcome that through repeated practice or exposure informs generic expectations for sonata form, or as proposing a ‘deformation’, expansion or stretching of that practice, which alters the expected course of musical action to a more expressive end.

Darcy and Hepokoski clearly state at an early stage in the text that this volume is designed to form part of an ongoing dialogue and should not be understood as an ultimate formulation of sonata form characteristics. Nevertheless, a primary motivation for them in undertaking this study is to propose levels of ‘defaults’ for each generic process of sonata form. These, they argue, assist the analyst in understanding precisely where departures from convention occur, how they interact with expectation and – perhaps most significantly – how the resulting expressive quality of such divergences can both define and influence the musical narrative of sonata form. To work towards this laudable end they suggest which musical attributes should be considered as defining aspects of the genre. The primary emphasis of the book, rather than a discussion of expressive potential or hermeneutic understanding, becomes the painstaking identification of a wealth of individual musical examples as illustrating, for example, a ‘first-level default’, a ‘second-level default’ or some degree of ‘deformation’ of sonata practice within each constituent section of the form.

The volume is divided into two weighty sections. The first begins with a brief overview of previous approaches to sonata form, both musicological and music-theoretical, and argues for a theory that is able to accommodate both conceptual stability and enormous diversity. Sonata form is defined as ‘a constellation of normative and optional procedures that are flexible in their realization’ (15). The immense pliability of this definition, however, is counterbalanced by the chapters that follow. These offer detailed and systematic analyses of discrete sections of ‘textbook’ sonata form (Hepokoski and Darcy's Type 3 sonata), introducing in the process new and highly specific analytical terms, symbols and nomenclature. Chapter 3, ‘The Medial Caesura [MC] and the Two-Part Exposition’, for example, comprises nine discrete subsections that increase in specificity from the general definition of a two-part exposition, to common options (or ‘defaults’) for medial caesura deployment, to the consideration of ‘declined’ and ‘deformed’ medial caesuras. The chapter closes with a section entitled ‘Troubleshooting MC Identifications’, which guides the reader through additional temporal, harmonic, motivic and dynamic possibilities that may help to clarify medial caesura categorization in challenging cases. The same exhaustive approach is adopted in the ensuing chapters, which cover continuous expositions, primary, transitional, secondary and closing subsections of expository material – each considered independently – the development, the recapitulation (normative and non-normative) and ‘parageneric spaces’ (that is, coda and introduction).

The second half of the volume is, for the most part, more streamlined, refining concepts introduced in the first part of the book over longer musical spans. Individual chapters or groups of chapters cover a handful of related sonata structures in their entirety: sonata form in minor keys, multi-movement sonata cycles, sonata form without development (Hepokoski and Darcy's Type 1 sonata), sonata form without tonic recapitulation of primary thematic material (Type 2 sonatas), rondos and sonata-rondos (Type 4 sonatas) and concerto form (Type 5 sonatas). The last of these, because of increased conceptual/definitional complexity, receives its own extensive study of more than one hundred pages.

In Sonata Theory a somewhat uncomfortable dichotomy exists between the fixed and the flexible, perhaps on account of the ambitious nature of the project and the enormous breadth of its coverage. The authors regularly argue for the recognition and embracing of ambiguities or ‘non-normative’ passages within their examples, and stress the importance of allowing musical material to be understood for what it is, rather than forcing it into predetermined definitional boxes: ‘the point is not merely to affix a label onto a passage of music (to force a decision in difficult circumstances) but to call forth the tensions and ambiguities at hand, ones presumably composed into the music’ (112). But however much the authors wish it were not so, the nature of their presentation suggests or implies that the theory should be read as a taxonomic scheme of classification. Detailed – and often compelling – attention is devoted to illustrations of how fairly brief excerpts of music compare to stylistic expectations and normative procedures, and/or how they diverge from them. An efficient thematic labelling system (complete with superscript ‘decimal designators’) has been devised to accommodate extremely precise differentiation between very similar thematic types. It is difficult, therefore, to divorce the analytic project entirely from a presumption that the underlying goal is, at least initially, to identify and label as many compositional variations as possible. In fact, the challenge the authors set for themselves early in the book is ‘to articulate the implied pattern-types that appear in some of the clearest or most notable exemplars and to do this with as much detail and specificity as the material encourages’ (8).

Tensions between the fixed and the flexible exist at deeper levels of discussion as well. The concept of compositional ‘defaults’, initially presented as the most common (but not the only) set of options available to a composer within a style, implies a certain degree of compositional autonomy. Further discussion, however, emphasizes both the conscious effort a composer must employ to depart from the most common practice, and the routine nature of compositional decision-making in more ‘normal’ circumstances. This suggests that composers working within a narrower set of stylistic options were less active in their decision-making about musical processes than those who moved beyond these expectations. The authors put it this way:

This characterization of the composer as a relatively passive agent, except when consciously stretching stylistic boundaries, becomes evident in other passages as well. Composers are described as ‘generating’ sonatas and devising ‘ordered system[s] of generically available options permitting the spanning of ever larger expanses of time’ (15) – descriptions of the creative process that seem oddly mechanical. The authors also stress that instances of ‘deformation’ are ‘never to be considered arbitrary’ (19), as if analysts must be reminded not to dismiss unusual passages as unconscious (or less than fully thoughtful) lapses on the part of composers.

Furthermore, it is not entirely clear how much the notion of ‘default’ rests with the composer, and how much with the listener. The authors argue, for example, that ‘analytical decisions involve assessments of tone and rhetoric that might differ from one person to another’ (59). This suggests that the degree of stylistic normality heard by one listener may not be heard by another – a proposal that should be able to be accommodated adequately within the flexible sonata definition on offer. In a discussion of the characteristics of Continuous Exposition Subtype I (Expansion-Section Subtype), the authors claim that

But too much emphasis on the peculiarities of individual listening experiences (or, for that matter, analytical readings) compromises, to some degree at least, the study's main premise: that it is both possible and productive to establish consistent levels within which analysts can evaluate compositional practices to a hermeneutic end.

Thus, despite its clear desire to push formal discussion into an analytical realm made newly meaningful, Sonata Theory, for the most part, views sonata form through a familiar lens – as a stylistically informed sequence of cadence-orientated musical sections that create a ‘structure of promise’ (18) to motivate the attainment of a structural goal in the recapitulation. That said, the magnification on the analytical lens is turned well beyond its usual setting, enabling the reader to revel in all sorts of previously underemphasized details. Given the theory's post-structuralist posturing, however, it is fair to ask how helpful this degree of specificity is in explicating the hermeneutic potential of a sonata movement. How detailed does a stylistic template need to be to prove useful as an idealized model against which real sonatas can be compared, particularly if the end result is a convincing hermeneutic reading? Does such an extensive differentiation of compositional choices provide the analyst with tools that offer additional clarification about what is going on in an individual sonata movement compared with the far less nuanced scheme with which experienced analysts are already familiar? One theoretical alternative to this awkward dependence on definitional specificity would be a more general discussion of formal function. The authors, however, despite frequent appeals to rhetorical character, seem reluctant to attach too much significance to functionality, criticizing Caplin for what they suggest is an over-reliance on this particular mode of analytical explanation.

In other ways, Sonata Theory does provide a new, more practically applicable analytical focus to sonata- form analysis. In addition to a stylistically determined harmonic arrangement across the form (or a ‘deformation’ thereof), the authors identify a referential rotational scheme underlying each movement. They argue that patterns suggested through musical domains such as texture, topic or other surface accentuation produce a significant and distinctive cycle of thematic modules that serves as a guide throughout the movement. The initial ‘referential rotation’ is introduced in the exposition, and thereafter it helps the listener to navigate successfully through the development, recapitulation and coda. As defined by the authors, ‘referential rotation’ is by no means a simple reiteration of the significance of the return of primary and secondary thematic material in the recapitulation. Rather, it is shown to be an indispensable analytical tool – a ‘foundational axiom of interpretation’ (613) – in clarifying the role of departures from expectation, particularly in the development and coda, where half-rotations, double rotations and episodic interpolations or substitutions are convincingly proposed and identified.

Despite the abundance of information that Sonata Theory offers, this information is not consistently accessible, and we are left to wonder for whom, precisely, the volume is intended. Much of the primary discussion of sonata form is initiated through the noting of stylistic conventions with which experienced music analysts will already be familiar. Indeed, the detail with which the authors describe accepted norms such as the thematic possibilities for closing material seems especially well suited to students, or to others who are quite new to sonata-form analysis and who are just beginning to familiarize themselves with the repertory. The index of works will be particularly useful in this regard, but one might wish for a further catalogue of musical examples by type, a series of flow charts outlining complex compositional options at a given formal juncture, or indeed case studies of a handful of carefully chosen Type 3 sonata movements in their entirety to accompany the existing prose. The more philosophical nature of other discussions in the volume, however, and the authors' particular desire to locate the theory within a much wider landscape of musical and extra-musical scholarship – Appendix 1 is devoted to positioning Sonata Theory within recent intellectual thought generally – suggest a desire to engage in a much more sophisticated scholarly debate about methodology.

All in all, there is much to stimulate debate in this volume. The authors are surely correct in suggesting that their remarks will initiate many new conversations about sonata form. There is no doubt that Hepokoski and Darcy's tome will be considered essential reading for all who wish to participate in a newly invigorated discussion. It remains to be seen whether Sonata Theory ultimately succeeds in identifying the hermeneutic potential of sonata form as a genre, in explaining how individual sonatas impart expressive meaning to analysts and listeners, or in providing a shortcut to stylistic understanding for developing analysts. At the very least, however, it will surely be valued for its encyclopedic compilation of interesting music-analytical observations on a wealth of sonata excerpts.