Some foreign cast recording trivia:
There's a 1997 Cast recording of Oliver! in Frisian (a language that is actually a cousin of English spoken by less than 1/2 a million people in the North of Holland)
There are a few cast recordings in Icelandic (a language spoken by less than a million people), most notably Little Shop and Evita.
In terms of foreign cast recordings, the leaders in foreign cast recordings are the Germans, followed by Spanish (both Latin American and Spanish cast recordings included), with the Dutch in 3rd place (remarkable since Holland is a small country).Speaking of the Dutch, there are quite a few shows that have recordings in Belgian Flemish as well as in Dutch (Belgian Flemish and Dutch are as simliar as British English and American English).
In terms of foreign musicals based on English language materials, there is the Czech musical of Fahrehnheit 451, the French Gone With the Wind (not to be confused with the upcoming Trevor Nunn directed London GWTW), and the French Romeo and Juliette.
It is also interesting to note that in Germany, many of the performers in musical theatre are American, English or Dutch. Helen Schneider, who is a big German musical theatre star, is originally from New Jersey but sings in German with virtually no accent. The Elphaba in the German cast recording of Wicked, Willemijn Verkaik (A European Idina Menzel sound-alike), sings German with a rather noticeable Dutch accent.
It is very important to change names in shows to locally acceptable names. Boq in Wicked was changed to Moq in German. Boq is a mild perjorative meaning " an idiot" or literally a "billy-goat".
The most famous instance where an American actress reprised her Broadway role in a foreign production (and recording) is Joan Diener in Man of La Mancha. Her French accent, incidentally, is nearly flawless.
Quite a few foreign singing stars ended up playing replacement roles on Broadway- The Israeli Jean Valjean, Dudu Fisher, ended up playing the role on Broadway (though he would not play on Friday night due to religious reasons). Pia Douwes, a Dutch musical actress, came to NY to do Chicago.
The jukebox musical craze has gone international....The songbook of Tsvika Pik, an Israeli pop singer and songwriter, was made into a hit jukebox musical called "Mari-Lu". Despite being critically panned, the show was a big heat. The show spoofed musical theatre conventions by having the female lead go to America to be a movie star but instead she becomes a prostitute in NY, where she finally gets rescued by the boy who was in love with her. Add the boy's evil step-mother and her two evil sons (one of whom ends up being a good guy and moving to San Francisco with his gay lover!).
"It does what a musical is supposed to do; it takes you to another world. And it gives you a little tune to carry in your head. Something to take you away from the dreary horrors of the real world. A little something for when you're feeling blue. You know?"