Of possible interest (or everyone may already know)
I once fell down a research rabbit hole about how 18th cent castrati might have achieved some famous vocal special effects.
I just encountered the Righteous Brothers live performance of Unchained Melody https://www.youtube.com/watch?v=m0EBs6uRgtw
I watched a video where someone ran the audio through some test gear, and other videos where voice coaches commented on how he was doing what he was doing.
I had a lot of deja vu.
He hit notes from D3 to G5.
#BaroqueSun
