I gathered that, as it is different than my other recordings.
I was particularly struck by the almost “dry” crispy clarity of her voice. It could have been the vocal placement, or the baroque lack of vibrato of which you spoke, but it was never sharp or shrill....just...different! I like it!
It could be that even with Classical music, modern amplification techniques tend to obscure some of that quality with excessive filtering and compression.
I love old-school acoustics, even though I am a sound engineer. I often stand away from the mic and balance my harmonies acoustically with other singers who ARE miked. It’s weird, but it works. Otherwise my harmonies are too loud.