Lowering the frequency of a sung note

[Gaston]

Hi,
if I lower the frequency of a note sung by a male voice, let’s say by a few tones, the voice “widens” in a monstrous way. Is there a way to preserve the timbre of the starting voice as much as possible?
Maybe applying some plugin later?
(The problem is also the opposite: if I raise the pitch a few tones, the voice becomes almost ridiculous).
Thank you,
g

[DVDdoug]

Melodyne (not free) has some “tricks” for dealing with that but I’m not sure how far you can push-it.