phantom higher extra voice revisted

i just saw a great 1-hour documentary about
John Phillips, leader and principal songwriter
of the 1960s group "The Mamas And The Papas".

at one point, i was stunned by an amazing coincidence:

in one segment, Denny Doherty (the other male
singer of the 2-male 2-female quartet) was
describing how they worked out the vocal arrangements
together and how John kept pushing them until
the overtones of the notes they sang created a
phantom 5th voice above theirs, which they
nicknamed "Harvey". and when they could all
hear "Harvey", they knew that their vocals had
the ethereal "locked-in" sound they were seeking.

this was stunning to me, because it's *exactly*
the same as the subject of Michelle Castellano's
presentation at the ISMA 2001 conference in Italy
(at which i also spoke), "Pitch perception: five voices
with four Sardinian singers".

-monz