My other big discovery in American Catholic church music is Bruno Oscar Klein (1858-1911), whose father was music director at the cathedral in Osnabrück and who studied with Rheinberger before coming to the US. He wrote an opera (Kenilworth, produced in Hamburg in 1895) and concert music, but was best known in his own time for his church music, which was widely performed and whitelisted.

Unlike Walkiewicz, he never wrote for reduced forces, or wrote down for amateurs. The apple didn't fall far from the tree, yet his stuff doesn't really sound like Rheinberger.

The motivation for this post is that I've discovered 2 performances on Soundcloud by a Berlin-based male quartet, MConsort, of an Iste Confessor and Salve Regina (Op. 28, no 3 and 4; score at imslp.org), the only 2 performances of Klein that I've heard. The quartet performance isn't ideal, lacking the solid sound that a choir would have (though to be fair, much of the Iste is for solo voice, and solo quartet performances might have been quite common). But it's more than adequate to display the music. I think this is music well worth doing. Your thoughts?

I also note a performance in June, for Klein's 160th birthday, of his Mass in Bb Op. 85, by the quartet CantOS, at St. Joseph's in Osnabrück. (pdf)