On Wed, 28 Nov 2007 01:14:28 GMT, "peter" wrote:
If you are singing real far off the mark, the box will glitch horribly. I
think it would be a disaster in a karaoke setup, but then again what do I
know?
In that case we need a pitch correction box that has two inputs: a vocal to
be corrected, and a reference pitch (the background music). The correction
is based on analysis of the chords in the music. This way, even if the
corrected vocal is not the intended note, it would at least harmonize with
the music 
This also solves the problem of the background music not being A440.
Are you absolutely SURE we need this? :-)