Schoenberg's appreciation, characteristically as generous as it is backhanded, brings the difficulties inherent in the notion of “Mendelssohn as progressive” into clear focus. On the one hand, it can be difficult to remember that his music was ever in any significant way “new.” “Progressive” more readily conjures up Wagnerian forays into the uncharted realms of the music of the future than the cultivation of the familiar, if daunting, confines of the past. Mendelssohn, however – alone among composers between Beethoven and Brahms – achieved his most characteristic and personal expression in sonata-form works, while, as Charles Rosen has observed, some of his more intimate lyric utterances may “charm, but they neither provoke nor astonish.”

Felix Mendelssohn was, like Brahms a generation later, one of the great pianists of his time, without having striven for a virtuoso career. On the organ he had no peer; virtually alone he popularized – in the best sense of the word – Bach's organ music, and his compositions for organ are a cornerstone of the post-Baroque repertory for the instrument. But his music for piano does not enjoy this status. Unlike Brahms, unlike his contemporaries Schumann, Chopin, Liszt, and unlike revered past masters such as J. S. Bach, Mozart, and Beethoven, Mendelssohn did not regard the piano as a preferred medium for his most significant artistic statements, and this attitude expresses itself in his choice of keyboard genres and in the dimensions and character of individual works. It is a question not of their quality – most of the keyboard music is of the highest order – but of how he weighed the importance of the genres that he cultivated. Nonetheless, his music for piano and for organ constitutes one of the more significant keyboard repertories of his century, and his contributions to the cultivation of serious keyboard music in public performance were, in their time, unsurpassed.

By his twenty-first year, Felix Mendelssohn had completed a handful of orchestral and chamber works that placed him among the front ranks of contemporary composers. Yet, as rapidly as a reputation was building around these pieces, it was not as a composer but as a conductor that he made his grand entrance onto the stage of Germany's musical history. On 11 March 1829, he directed the Berlin Singakademie in a revival of Bach's St. Matthew Passion, unheard since its composer's death and thought, in Mendelssohn's time, to have been premiered exactly a century before. Upon receiving word of the event, Goethe famously observed to his friend –Mendelssohn's teacher – Karl Friedrich Zelter, “To me, it is as though I have heard the roar of the sea from a distance.”

The “Bach revival” that feverishly ensued had hardly been conjured ex nihilo by the young conductor: the Singakademie had offered occasional motets and cantatas of Bach's since its 1791 founding, first under the direction of Christian Friedrich Carl Fasch, then, after 1800, under Carl Friedrich Zelter; and by 1829, Bach's generally neglected choral music (his keyboard music had never passed wholly out of currency) had found an important outlet, too, in Frankfurt's Caecilienverein. But there was no question that the 1829 St. Matthew Passion revival – abbreviated though the work was through the excision of six of the chorales, some recitative, and all but two of the arias – constituted an event of epoch-making significance in the revitalization of Bach's reputation.

There can be little doubt that Mendelssohn's star, just fifty years ago threatened with obscurity, is again on the rise: his works are more prominently represented in musical life than at any time since the mid-nineteenth century, and the scholarly literature concerning him is more voluminous and more diversified than ever. The recrudescence becomes all the more remarkable if we consider the extraordinary difficulties it has faced – for since the 1850s Mendelssohn's critical reception has centered on ideologically extreme positions. For the last decade of his life he stood at the center of European musical culture and was widely hailed as the personification of modernity, but by the mid-twentieth century his music was portrayed as having been archaic and epigonic even in its own time. Some critiques amounted to little more than ludicrous lionization, portrayals of Mendelssohn as a musical messiah whose death had robbed the musical world of its only real prospect for future salvation from the turmoils of the present; others descended rapidly into equally vapid dismissals, vitriolic tropes on the political controversies of the day that found in Mendelssohn the epitome of many issues that cried out for drastic reform. Mendelssohn was granted little role in the great narrative of nineteenth-century music history as it was written by these self-styled progressives, and many musicians and other music-lovers fell prey to that assessment even after the ideological underpinnings from which it originally derived had fallen from favor. In a word, the verdict was retained even though its evidentiary foundations and reasoning had been renounced.

Mendelssohn began composing songs as a child – his setting of “Raste Krieger, Krieg ist aus” of 1820 anticipates Schubert's setting of the same text from Sir Walter Scott's The Lady of the Lake by five years – and continued to engage the genre throughout his life. One scholar has observed that in the span of twenty-eight years from 1819 to 1847, there was scarcely a single month in which he was not occupied with song composition. He published fifty-four songs with opus numbers (opp. 8, 9, 19[a], 34, 47, 57, and 71) and thirteen without opus numbers during his lifetime; after his death, thirty-one additional songs have been published, with approximately thirty-five either unpublished or available only in facsimile. But the 135 or so songs have often received less than their due, in part because many are apt for performance by amateurs, because they reflect salon culture in Vormärz Berlin, and because their composer does not probe Romantic subjectivity after the fashion of Schubert or Schumann. Reappraisal of Mendelssohn's lieder, however, reveals greater variety and depth than some have supposed. There are songs which make few concessions to an amateur musician's limitations, such as “Andres Maienlied” (Another May Song), op. 8, no. 8, or the “Reiselied” (Journeying Song), op. 34, no. 6; there are songs which acknowledge complex poetry in complex ways; there are poetic tastes to be accounted for and an aesthetic of song composition to be defined. This repertory holds riches still to be mined.

Though scholarship is generally agreed about the prominent position in Felix Mendelssohn Bartholdy's oeuvre of sacred music, how to assess its role for his identity as a composer has generated contrasting lines of inquiry. We shall begin by briefly considering the dynamic of religion in the composer's family, and then propose some ways in which the dynamic played out in his sacred choral and chorale-related works.

As the grandson of the leading Jewish philosopher of the Aufkärung, Moses Mendelssohn, Felix was of course mindful of his Judaic roots, which encouraged some scholars to search for Jewish influences in his music. As early as 1867, Camille Selden assumed that Felix had frequented a synagogue and was well versed in Hebrew; two years later, Hippolyte Barbedette was able to hear in the composer's music echoes of Jewish psalmody. In 1880, Sir George Grove, whose pioneering encyclopedia article set the foundation for modern Mendelssohn research, assessed his setting of Psalm 114 op. 51 (“When Israel out of Egypt came,” 1839) thus: “The Jewish blood of Mendelssohn must surely for once have beat fiercely over this picture of the great triumph of his forefathers, and it is only the plain truth to say that in directness and force his music is a perfect match for the splendid words of the unknown Psalmist.” More focused attempts to trace Jewish elements in Mendelssohn's music ensued in the second half of the twentieth century.

With the exception of Robert and Clara Schumann, no relationship between two European musicians of different genders is as famous as that of Fanny Hensel and Felix Mendelssohn Bartholdy, siblings who have always been linked in biographical depictions. Many of Felix's first published letters, appearing in the two decades after his death, were to Fanny, and the memoirs of friends such as Ferdinand Hiller, Eduard Devrient, and Ignaz Moscheles, who knew him from childhood, all mention his talented sister. Awareness of Fanny's musical abilities spread well outside the family circle during her lifetime; as early as 1830, John Thomson, writing in The Harmonicon, declared that Fanny composed “with the freedom of a master.” After her death, but even before the family history by her son, Sebastian Hensel, was published in 1879, recognition of “Mendelssohn's sister” began to appear in wide-ranging sources. The biographical dictionaries of Carl von Ledebur and François Joseph Fétis, both from the 1860s, contained entries on Fanny. In his 1869 inventory, Hereditary Genius, British scientist Francis Galton listed both Mendelssohn and his “very musical” sister, described as “of high genius.”

A popular, somewhat pretentious, party game in certain circles not so long ago was to summarise a famous work of literature as briefly as possible: give the plot of Proust in one sentence, and so on. If we were thus to reduce the storylines of the Iliad and the Odyssey to the bare essentials, the Gods would not have to feature at all. Zeus’s co-operation is not necessary, given the hero’s larger-than-life status, to explain the disastrous effects of Achilles' withdrawal from battle, and neither do Poseidon or the Sun need to be invoked to account for misadventures at sea and the effect of twenty years' absence on a man’s home. The party game was of course intended to provoke amusement by making the summary factually accurate but also entirely incongruous with the spirit of the original. Similarly, without the Gods the epics would be quite different from the Iliad and the Odyssey that we have, and surely also from the tradition that produced the poems. The (slightly longer) summaries given by the poems themselves, after all, give divine action a certain prominence: 'the plan of Zeus was accomplished', 'he took away from them the day of their return'; and the action of the Iliad begins with the question 'Which God caused them to quarrel?' The words of the characters reflect a pervasive view that significant ideas, emotions and events are in some way caused by the intervention of a God. Insofar as some concept of cause and effect is inherent in narrative, then, the divine must make its appearance; arguably it is not until Thucydides that the idea of a sustained narrative without the divine is born.

How and by whom were the Iliad and Odyssey composed and preserved?

Certain anticipations apart, the modern debate began in 1788 with the publication by Villoison of the scholia in the tenth-century manuscript of the Iliad, Venetus Marcianus Graecus 454. These marginal notes preserve substantial remnants of ancient scholarship on the poems, going back as far as third-century BC Alexandria and permitting inferences about the earlier state of the text. Starting from the premise that Homer lived in an illiterate age (a premise which, ironically enough, we now know to be false), and using the new evidence, F. A. Wolf in 1795 argued that the poems as we have them were put together by a compiler living long after Homer, who had been a simple singer of heroic lays. The game was then to detect by analysis of the poems which bits derived from the original Homer, and which bits from later bards or editors; of these epigoni most scholars working in the analytical tradition (Wolf himself excepted) had a low opinion. Their handiwork was betrayed by inconcinnities, inconsistencies and repetitions in the poems, allowing the scholar to determine which parts had been composed independently of each other and in what order; by these means a wonderful variety of theories emerged, dividing the poems up in different ways and placing 'Homer' at various points in their evolution. Nowadays critics tend to explain most of these irregularities by reference to the exigencies of oral performance.