For the last two performances of Rodelinda at San Francisco Opera, tenor Paul Nilon was replaced by Kobie van Rensburg and bass Umberto Chiummo was replaced by Joshua Bloom.
Van Rensburg was in the Met Rodelinda cast last year and got excellent reviews. I can see why; he has excellent agility and a good trill, both required for singing Handel. But that voice! It's not especially interesting; his tone is shallow; it's starting to show some spread on top at forte - not good in a singer who is only in his mid-30s. He got a good hand after each of his arias, and pretty much earned it - I'd rather have heard Nilon again, though. He's not quite as agile as van Rensburg. He does have a much more attractive voice.
I liked Chiummo just fine and would have been happy to hear him again. Joshua Bloom, though, has got an outstanding voice, very firm and dark, and more vocal and stage presence, overall. The last young bass who made this kind of impression on me was John Relyea, another Adler Fellow. I expect Bloom will also go on to great things and a fine career, and I'm definitely looking forward to hearing him in the future.