Meyerbeer – like Halévy, Auber, and several other contemporaries – has mostly disappeared into a black hole. Even in France he is mostly ignored (although he worked primarily in France, he was German by birth).
Richard Wagner had personal differences with Meyerbeer (mainly rooted in private jealousies that Meyerbeer’s music was so successful by comparison to his own works at the time – and his perilous financial position for much of his life). However, this does not completely explain the disappearance of Meyerbeer’s works from the repertoire in the 20th century, which seems to be also related to fad and fashion. It’s the entire genre of French grand opera which has fizzled out.
It can be claimed – but without any real justification – that Meyerbeer and Halévy were discriminated against as Jews, but this doesn’t explain why Auber (who had been enormously popular) has dropped off the radar entirely … why Gounod’s works are rarely performed (except for Faust) … why Bizet’s other operas (except Carmen – does anyone even remember them, except for their overtures?) are never staged … why Delibes is utterly ignored … why even Massenet is relegated to the Johnstone’s Paint Trophy League.
For me, I’m afraid, the axe-grinding excuse of anti-semitism doesn’t explain any of this … there are too many non-Jewish composers in the same genre who are ignored too. Nor does the word of Wagner, which is a red herring – what opera manager takes Wagner’s views into account when programming a season nowadays?
In short, Meyerbeer’s French grand opera is clearly out of fashion these days. Vast amounts of utterly bloated bombast, a dearth of melodic imagination, and the most ludicrously melodramatic plots, reedemed by the odd inspired moment and a certain dramatic sense. L’Africaine is probably the best (or least bad) and has a few genuinely striking sections. Robert le Diable, the opera that truly established his reputation, was a massive success in the Paris of the July Monarchy; nowadays it works as an unintentional comedy (try the scene in Act 3 with a chorus of dead nuns rising out of their coffins). There’s a pretty good section on Meyerbeer in Charles Rosen’s The Romantic Generation; also worth reading for those interested to know more about the composer are Jane Fulcher’s The Nation’s Image: French Grand Opera as Politics and Politicized Art, Heinz and Gudrun Becker’s Giacomo Meyerbeer: A Life in Letters, and Mark Everist’s collection of essays Giacomo Meyerbeer and Music Drama in Nineteenth Century Paris.
The whole genre of French grand opera (encompassing the works of Meyerbeer, Halévy, Auber and some of the later works of Rossini, and becoming influential on the work of Donizetti, Verdi and even Wagner) is certainly of great interest to those wanting to understand better the cultural history of the period; the works are worth hearing a few times, but I’d be very surprised if they would stand up to the numbers of repeated performances and productions that would lead to their being incorporated into modern standard repertory.