Dear Jo !

As I am actually a second base
I use my falsetto for the "female" upper voices !
You may know that all male barbershop tenors
use falsetto as it would be absolutely impossible to
reach as high notes as is required by the arrangements
without using falsetto. To my own surprise I have
found out that many bases have very good falsettos and
then there are those guys like Tim Waurick who can sing
9 octaves !! (check him out on utube) !!

Cheers
Dani