From what I've read I don't think the tenor Alyeya is quite unsupported by evidence - I seem to recall reading that the surviving material only has a treble clef for him, as for all the other tenors, and that Mackerras has said he would also use a tenor from here on in. That's very hearsay though and I haven't been able to find anything solid. Over to Opilec, I think.

Thanks to Ron for drawing this broadcast to our attention. I mentioned the performances to one of the producers at Afternoon on 3 ages ago (at about the time of the Holland Festival performances), so am glad it's finally being given an airing over here.
I saw the production in Vienna in May, travelling out there just for the one night. It was an extraordinary piece of music theatre, an absolutely knockout evening. Huge ovations, an uncompromisingly hard-hitting, non-gimmicky production. I felt emotionally and physically drained afterwards. Then I was taken backstage to meet Boulez! (And also had a chat with Chéreau!)

Concerning the tenor Alyeya, the head of the editorial office at Universal Edition (the work's publisher) advised me while I was in Vienna that, in the process of preparing the new edition used for these performances, it had emerged that it was now thought Janáček intended the part for a tenor. He cited the fact that only treble clefs are used for the tenor voices throughout (i.e. not a treble clef with an
octava sign underneath). He told me that this was now John Tyrrell's view, and that Mackerras, no less, had declared that if he were to perform the work again (I do hope he will!), he would do it with a tenor Alyeya.
A few weeks later, I mentioned all this to John Tyrrell, who's actually editing the work for UE's new edition (he'd answered hundreds of queries from Boulez in the course of preparations for the production). He almost exploded! He says it's absolutely clear, both from the manuscripts and from supporting documentation, that Janáček intended Alyeya to be sung by a soprano, not a tenor. John knows the sources of this opera better than anyone, having worked on it in great detail for many years. So his word is good enough for me. (John's been so busy, both with the
House of the Dead edition and with his Janáček biography, that he's one of the few members of the Janáček fraternity
not to have seen the production!)
I suspect that my friend at UE might have been spinning a little in support of the Boulez/Chéreau production (which was very big indeed on the European festival scene this summer).
Having said all of which ... it
worked with a tenor. Thanks partly to the extraordinary direction and acting, partly due to the fact that the tenor concerned (Eric Stoklossa) is young and not only looks it but sounds it (I mean that in the best sense). So it didn't feel like such a terrible jolt as all that. But, having consulted the Janáčkian oracle, I wouldn't want to hear it sung by a tenor every time. I'm glad I have though: performances are rare enough as it is!
Friends from Brno were, on the whole, in favour of a tenor. One of them, who's a Janáček authority in his own right, approved: his wife didn't!
Do try to tune in on Thursday if you can: it's stunning. But hopefully at some point a DVD will appaer (the Aix performance was filmed): audio alone can't really do it justice.
Cheers,
Opi