I happend to mistakenly stumble across a documentary about the 18th century vocal phenomenon of the castrati (and their modern counterparts the contralto) on the now defunct (shut down two days ago, in the name of economic progress, by the current Greek government) Greek public television station ET1, and was astounded at their vocal capacity/capability.
Here are a couple of examples:
You can find information about the documentary here http://www.ticofilm.com/Tico_Film_Company/HV_EN.html
With the eye of wisdom we discover a lot of anger in us, any amount of jealousy, resentment, ignorance, desire - mountains of emotion whose existence we would never have suspected in ourselves... We recognize that most of the faults we perceive in others are only the mirror of our own negativity, the reflection of our own disturbed feelings... At the same time, we relieve the world around us of the burden of our own negative judgements."
Gendun Rinpoche Heart Advice from a Mahamudra Master