Bob Draper wrote:

>Can I ask a question under this topic please? As I understand it a
>castralto used to sing alto and male soprano.

Not castralto Bob, rather, castrato.  In other words a young male who was
posessed of a lovely prepubescent voice would be castrated before puberty
so that his voice would not change.  As a result, he could sing in the
register of a female alto or soprano with the full chest power of a fully
grown man.  The last castrato lived to record a few 78 rpm sides, and the
disc is available on Pearl.

>Now, an alto is also called a counter tenor and a female singing the same
>part is a contralto.

No, a counter tenor is a counter tenor and a contralto is a contralto.  A
counter tenor is a man, a contralto a woman.

>Assuming that this is correct then what is falsetto? Is it when a man sings
>alto, soprano or both? Hence is alto considered to be a natural register
>for a man?

No it is not the natural register for a man.  A counter tenor (more
appropriately called a falsettist or sopranist,) is a male singer who has
a highly cultivated falsetto.  Falsetto is a phenomenon of the male voice
in which he is able to sing above his natural register by a different
physical use of his vocal folds than in regular singing.  (I am sorry that
I can't explain the physiology of it all.) It is still common for English
Cathedral Choirs to use counter tenors for the alto parts in choral music,
especially that of the renaissance, when women were not permitted to sing
in church anyway.  Many rock stars (Getty Lee of Rush for example) and pop
groups (The Bee Gees for the most striking) use falsetto to sing as high as
they do.  Women are physically unable to sing in falsetto.

Kevin Sutton