Almost Angels : Strauss Opera?

It ssems to me, that the cute little musical extravaganza the boys gave dressed as girls was called a "Strauss opera." However, while many popular pieces were used for this segment, including the Radesky March, I don't think this was a Strauss opera at all. Please feel free to contradict me if you know better.

No, no contradiction.
It was just a way to highlight the choir. In fact, as well as 'THE RADESKY MARCH' there was another 3 'bits' from classical music - and not all Strauss.

b.t.w. perhaps you might like to read my coments in 'available on DVD' question

Actually the opera is an expansion of "Tales From Old Vienna," which was an operetta that was performed (to piano accompaniment) at many live conerts by the Vienna Boys Choir. (Unfortunately the operettas have discontinued.) "The Radetzky March" was by Johann Strauss the elder, whereas Peter's solo in the film was sung to the tune of "Roses From the South" by Johann Strauss the son.