Developments in the understanding of eighteenth-century opera over the past quarter century have been profound and far-reaching. Drawing back from a near-sighted preoccupation with a small number of canonical works, music historians have begun to appreciate the extent to which individual operas inhabited a richly populated operatic – and more broadly theatrical – landscape. Detailed historical investigation of a variety of local traditions has led to an awareness of the extent to which operas draw meaning from their participation in ‘conversations’ (to use Mary Hunter's term) with other works. At the same time, the theoretical terrain has been refashioned by the recognition, on the one hand, of the audience's constitutive role in the operatic experience and, on the other, of operas' volatile existence as unfixed and changeable texts.

Signs of these shifts are easy to detect in the introductory chapter of the Cambridge Companion to Eighteenth-Century Opera, the newest addition to a highly successful series of guides notionally directed at the advanced undergraduate student, but also of value to a broader readership. Seeking to counter an ontology that treats operatic works primarily as circumscribed historical facts, the volume's co-editor Pierpaolo Polzonetti reflects on opera's capacity for (and dependence on) perpetual, and perpetually varying, recreation. The unpredictable ways in which operas unfold and evolve through time are demonstrated with reference to the picaresque history of Vivaldi's Motezuma, a work that might almost have been conceived explicitly for this purpose.

Polzonetti's concern with (re)creation sets the tone for the book's first section (‘The Making of Opera’), which examines a pleasingly diverse selection of aspects of the eighteenth-century ‘operatic event’. Alongside accounts of the Metastasian libretto, orchestral idiom and operatic scenography, a number of issues commonly neglected in generalist accounts come under consideration here. Gianni Cicali's wide-ranging discussion of acting style directs valuable attention onto (among other things) the interface between opera buffa and prose comedy, and Rebecca Harris-Warwick's account of ballet gives an overview of a frequently overlooked component of operatic performances. Given the emphasis on ‘making and remaking’ opera, the exclusion of performers, specifically singers, from detailed consideration is surprising. In particular, an acknowledgment of the centrality of improvisation – perhaps within the context of a wider discussion of vocal style and performance practice – would usefully have borne out the ideas of perpetual reinvention and dispersed authorship laid out in the first chapter.

In general terms, the most successful essays in this section balance a broad overview of their topic with one or more close readings or case studies, a procedure that allows for the efficient integration of new or revisionist interpretation with the digest of prevailing knowledge expected in a reference source. Thus James Webster offers a comprehensive taxonomy of the (Italian) operatic aria and its formal attributes before using a reading of ‘Pensieri, voi mi tormentate’ from Handel's Agrippina to prod at the boundaries of the static/kinetic schema students will have encountered as established wisdom. In turn, the detailed (if somewhat laconic) linguistic analysis of ‘Fra cento affanni’ from Artaserse with which Paologiovanni Maione concludes the Metastasio chapter may well spur English-speaking scholars on to engage in more active consideration of the sound of sung Italian (the inclusion of this type of close reading, practically unknown in Anglo-American musicology, is one of the benefits of the volume's impressively multinational collaboration).

This model is not always so effectively deployed, however. Caryl Clark's chapter on operatic ensembles stretches the boundaries of the ‘long’ eighteenth century to include a lengthy discussion of Rosina's aria ‘Contro un cor’ from Rossini's 1816 Il barbiere di Siviglia. Clark's reading of the number as an ‘aria ensemble’, imaginative though it is, broadens the concept of ensemble in ways that are problematic and fail to acknowledge the altered generic context of the early nineteenth century. Although Paisiello's 1782 working of the subject is invoked as an alibi, three eventful decades separate the two operas, and Rossini's work can hardly be seen as representative of an eighteenth-century aesthetic. The reader may be left with the sense that the Companion format is not the best forum for tangential interpretations of this type; in the circumstances, space might more usefully have been devoted (for example) to a discussion of the eighteenth-century operatic duet. Meanwhile, the dense weave of Alessandra Campana's closely argued essay on Don Giovanni's visual dimension sits somewhat oddly in the company of the other contributions, eschewing as it does the leap outwards from close reading into a broader statement of principles.

The second half of the book parses its topic by geography, with essays devoted to local or national traditions. Inevitably, given the nature of the eighteenth-century operatic economy, the hegemony of Italianate style looms (only the chapter on France confines its purview rigorously to French national genres). Describing the extraordinarily varied ecology of the eighteenth-century English musical stage, Michael Burden reflects on the lack of public appetite for English-language opera in the Italian (that is, all-sung) style, while Estelle Joubert deals with a rather more productive encounter between homegrown German and imported Italian idioms in her account of Dittersdorf's Doktor und Apotheker. In small but telling ways, however, the collection works to nuance the concept of Italian dominance. For one thing, there is no chapter devoted to opera in Italy itself; in its place, Anthony DelDonna provides an account of opera in Naples. While it might be argued that Naples and Italy were, operatically speaking, all but synonymous from the 1730s onwards, the concentration on local genres – including dialect comedy and the peculiarly Neapolitan form of Lenten opera – may prompt the reader to reflect on the nature of Italian musical cosmopolitanism. More subversively, Louise K. Stein's and José Máximo Leza's rich account of opera in the Hispanic world has the effect of inverting the centre/periphery structure implicit in much opera historiography, reminding the reader that for a substantial period Italy (specifically Naples) was marginal with respect to the more powerful Spain. Stein and Leza give the reader much to ponder regarding the effects of and opportunities arising from the importation and exportation of operatic works, a topic that has been too little studied. In fact, the treatment of opera on the Iberian peninsula and in the New World emerges as one of the book's great strengths. The demonstration of the role of Spanish taste as a crucial mediating and conditioning factor in the dissemination of Italianate style ought to serve as a salutary corrective to the persistent north European focus of most opera histories.

Taken as a whole, this collection will do much to broaden its readers' outlook. However, the book is marred by problems of readability, at times requiring the reader to pick a way through prose that is anything but pellucid. Some awkwardness appears to result from over-literal and unidiomatic translation (and mistranslation: on a number of occasions, the Italian melodramma has been rendered, incredibly, as ‘melodrama’). But mixed metaphors and tangled idioms are also a feature of more than one of the English-language contributions (the delicious ‘this idealized sphere served as a platform’ (187) deserves recording for posterity). Confronted with phrases such as ‘staging this tale implies that action should prevail on abstract dichotomies’ (72–73), the frustrated reader may be left wishing for evidence of more muscular editorial intervention.