Anita Cerquetti singing Rezia's 3rd Act Prayer of Weber's opera Oberon. It's such beautiful music I really don't understand why this isn't done more often. The opera itself (based on a quick listen with a pretty, er...interesting but ultimately unideal cast) seems a bit of a hodge podge that doesn't seem particularly unified, but I'd have to look into it more.

Still, this is real good singing.