This may not be actually be the strangest choice of repertoire that a famous conductor has made, but it's up there. A few days ago, the conductor Nikolaus Harnoncourt, one of the fathers of the early-music movement who also built a successful parallel career conducting 19th century European music (his recordings of Beethoven, Schumann and Dvořák are mostly very fine) decided to conduct his first work of 20th-century American music... Porgy and Bess. At the Styriarte Festival in Graz, he led concert performances of Gershwin's jazz opera; Canada's Measha Brueggergosman was originally supposed to be Bess, but unfortunately had to pull out due to illness.
Harnoncourt has made some strange repertoire choices before, including a legendarily bad recording of Verdi's Aida, but the sight of one of the most ultra-European musical figures (he rarely works outside Europe) trying to lead a jazz/musical-comedy opera with an all-black cast -- but with his regular chorus, the Viennese Arnold Schoenberg Choir -- was about as bizarre as it gets. Particularly since visual evidence suggests that, even in a concert without costumes, the staging managed to be kind of Euro-trashy. It's not quite the equivalent of Kiri Te Kanawa and Jose Carreras singing West Side Story, but it's close.
There will be no recording, of course, but there audio excerpt available online; it features the opening of Act 2 scene 2, with a chorus followed by "It Ain't Necessarily So," and while the song is pretty standard (it's an unkillable song), the chorus sounds like nobody has any idea what they're singing about or what these rhythms are supposed to signify, and the conducting is slow, strange and square. (Though to be fair, it's really no worse than parts of Simon Rattle's famous Porgy performances/recording.)
For all that, I like Harnoncourt a lot; he's actually one of my favourite living conductors, because while he is often bizarre, he's rarely completely uninteresting. (Even his recording of Aida has a certain perverse fascination as long as you don't expect it to be, you know, good.) He's one of those guys who approaches every work with a "concept," often based on weird readings of character motivations or what the composer was thinking, and then he interprets the music in light of whatever he happens to think it's about. When the concept makes sense, it can lead to interesting performances, and while he's not a technically brilliant conductor, he's very good at getting a distinctive, biting sound out of any orchestra he works with (and the ability to execute a concept and create his own sound are more important, for a conductor, than having the clearest time-beating skills).
(Cross-posted at TV Guidance.)