This is simply the best book yet published on Handel's Messiah, and I expect it will remain so for a very long time. To be sure, its author has had the good fortune of being able to build on the work of superlative predecessors. Ruth Smith's revelatory study Handel's Oratorios and Eighteenth-Century Thought (Cambridge: Cambridge University Press, 1995) provides essential reading on the history of ideas. Hamish Swanston's Handel (London: G. Chapman, 1990) offers a remarkably insightful delineation of contemporaneous theological currents. Richard Luckett's Handel's Messiah: A Celebration (London: V. Gollancz, 1992) provides an enlightening cultural and social backdrop to the genesis of Handel's work. And Donald Burrows's Handel: Messiah (Cambridge: Cambridge University Press, 1995) makes available an indispensable compendium of textual and musicological information.

What has been lacking in the extensive literature on Handel's Messiah, however, is a thoroughgoing analysis that perfectly integrates the textual, musical and theological aspects of the oratorio. This is Erhardt's achievement, and one for which he is ideally and uniquely suited. He studied baroque violin performance at the Koninklijk Conservatorium in The Hague, and earned a degree in musicology from the University of Utrecht. He has a degree in theology from the University of Oxford, where his studies included reading the Bible and the writings of the Church Fathers in their original languages. More recently, at the Roosevelt Academy in the Netherlands, he has been teaching not only theology in the Department of Religious Studies, but also performance practice and music theory in the Department of Music.

Erhardt claims indebtedness to the field of theological Bach research, but the quality of his work, in both its methods and its results, far surpasses that of his typical Bach colleagues. Nearly all members of the (only recently defunct) Internationalen Arbeitsgemeinschaft für theologische Bachforschung have given short or no shrift to Bach's music, electing to focus only on the liturgical poetry Bach set. Many of them write in such convoluted German, employing the most needlessly uninviting theological argot, that hardly anyone – including scholars of religion – can ascertain what on earth they are talking about. To make matters worse, most of them also seem much keener to act as apologists for modern orthodox Lutheranism than as historically informed exegetes of Bach's output. Erhardt is refreshingly free of these faults: he discusses both text and music at length; he writes in remarkably smooth, transparent German; and he makes no effort to defend the church.

Erhardt divides his illuminating and accessible study into three parts. In Part 1, he examines Old and New Testament concepts of God's ‘Anointed One’ (the Messiah), drawing extensively on recent Anglo-American biblical scholarship. Next, he reports on the personality and interests of Charles Jennens (1700/1701–1773), the librettist for Handel's Messiah, as demonstrated in large part by the musical, theological and other scholarly holdings in Jennens's massive personal library. Part 2 first discusses general formal aspects of the libretto and then focuses on close textual and musical analyses of each of its numbers. Part 3 is in the way of an appendix: it includes a table of cross-linked textual themes in the libretto, an overview of the libretto's biblical passages that are taken from the Book of Common Prayer and an index of parallel passages from the Old or New Testament respectively for the verses quoted in the libretto. Most significant, however, is Erhardt's spectacular reconstruction (of more than fifty pages) of the list of theological titles in Jennens's library.

The heart of the book is, of course, Part 2. Here Erhardt wends his way through Messiah scene by scene and movement by movement. First he lays out a diplomatic facsimile of Jennens's respective biblical passages. Then he explores current linguistic and historical research on their underlying ancient Hebrew and Greek source texts. This he follows with detailed reporting on scholarly and devotional treatment of the verses in the books from Jennens's library. Finally he moves to a critical survey of the scholarly reception of Handel's settings and concludes with his own richly insightful, textually and musically integrated analyses.

Among the principal findings of Erhardt's book, a big surprise is the depth of Jennens's indebtedness to one title in his library, Richard Kidder's virulently polemical A Demonstration of the Messias, in which the Truth of the Christian Religion is Proved, against all the Enemies thereof; but especially against the Jews, second edition (London: for John Osborn, Thomas Longman, Richard Ford, Aaron Ward, Samuel Billingsley, 1726). In Handel's Oratorios Ruth Smith had already pointed out that Kidder's list of contents reads like a blueprint for Jennens's libretto (150). Erhardt, however, ascertains that Jennens's reliance on Kidder is rather more far-reaching, indeed pivotal. This is not only a quantitative matter of how many of the biblical verses that Kidder cites are quoted in Jennens's libretto; more important still is Erhardt's qualitative assessment of A Demonstration of the Messias (see pages 77, 110, 129, 134, 147, 180, 202 and 241), which establishes that in compiling his libretto Jennens relied very heavily on Kidder for particular juxtapositions and formal placements of the Bible verses. Moreover, Erhardt is in fact the first to take proper note of the significance of Kidder's full title.

In the secondary literature predating Erhardt's study, Kidder had been mentioned occasionally as a source for Jennens's anti-Deism. While Erhardt helpfully further documents Jennens's anti-Deism, his research on the extent to which Kidder's theological anti-Judaism informed Jennens's work on Messiah counts among Erhardt's most noteworthy, original contributions to Handel studies.

Let us consider just one example of Jennens's anti-Judaism, from the very opening of Messiah, where the libretto moves from Isaiah 40:1–5 to a juxtaposition of Haggai 2:6–7 and Malachi 3:1–3. Kidder juxtaposes these same biblical passages and writes concerning them, at Part 3, page 17: ‘GOD hath given us notice, that he would put an end to the institutions of Moses [that is, Judaism, by destroying its Temple], in the days of the MESSIAS [that is, Christianity].’

According to the traditional Christian interpretation developed in Kidder (and in other authors from Jennens's library), Malachi 3:3 – the text of the second chorus in Messiah, ‘And He shall purify the Sons of Levi, that they may offer unto the Lord an Offering in Righteousness’ – points to the year 70 A. D., when the Jerusalem Temple was destroyed. In this view, Jesus – seated in heaven at the right hand of God the Father, forty years after having been crucified – vented his anger, via the Roman armies, at Jewish failure to accept him as God's Messiah. This traditional Christian understanding teaches, furthermore, that old Israel's Temple priesthood had worshipped God carnally by offering material sacrifices and teaching the Law of Moses, whereas the purified priesthood of God is active in a new, converted, spiritual ‘true Israel’ – the Church – which worships God properly: through and in Jesus, God the Son. Thus Jewish worship, centred on the Law of Moses, is obsolete, and is entirely superseded by Christian worship, which is centred on the gospel of Jesus.

Now there is nothing necessarily wrong with Christological appropriation of texts from the Hebrew Scriptures, or with Christian disagreement with Judaism. Generally when Erhardt uses the potentially loaded word ‘anti-Judaism’, the context makes clear that by ‘anti’ he simply means ‘in disagreement with’. (Doubtless all forms of Christianity, to varying degrees, are ‘anti-Jewish’ to the extent that they do not agree with the various forms of Judaism that reject Jesus as God's promised Messiah.)

More difficult and emotionally controversial, however, is the question of whether ‘anti-Judaism’ in that general sense of ‘disagreeing with Judaism’ ever spills over into ‘anti-Judaism’ in its more specific and, I should think, morally repugnant sense of ‘teaching contempt for Judaism’. Erhardt does not fully address this issue, though he cannot be faulted for not having done so in an already so wide-ranging book. (For arguments on anti-Jewish Schadenfreude in the ‘Hallelujah’ chorus, see my article ‘Rejoicing against Judaism in Handel's Messiah’, The Journal of Musicology 24/2 (2007), 167–194.)

To conclude this review, and in the interests of full disclosure, I should mention that I have been a friend and colleague of Erhardt's for nearly a decade. Additionally, I enjoyed the great honour of serving as an examiner on his doctoral committee, whereas Erhardt has had the arguable misfortune of agreeing to vet my occasional ventures into the world of Handel scholarship. Tassilo Erhardt's superb study deserves the widest possible audience. The unfortunate and harsh reality is, though, that so long as this book appears only in German, published by a relatively minor press, its readership will be limited. What is needed, straight away, is a top-level English translation from a major publishing house.