Harmonizer questions

[hsut@ec.purdue.edu (Bill Hsu)]

Thanks to Greg Earle for the correction about Laurie Anderson's Harmonizer.
By the way, how does this thing work? Does it digitally do pitch
extraction, change the pitch frequency and spit out the new signal,
or is it some kind of funky analog technique? The pitch extraction stuff
I've read about doesn't always work very well, but I guess you probably
don't worry too much about distortion when you're doing weird vocals. 
Laurie Anderson's Harmonized voice sounded pretty intelligible, tho...

(When I see "Harmonizer", I think of some device which takes as input
some melody, and you can put it on "Mozart mode", "Wagner mode",
"Schoenberg mode" or "Coltrane mode" to get different harmonies :-)

Bill Hsu