question about sounds and stuff...

hi, I’ve been trying to find a good program to edit sounds and I found audacity and it’s pretty good, but not good enough. You see, I’m trying to do an auto-tune effect but the audacity plugin is not working for me and I found another program called Melodyne but it’s not free, so my question is: is there any free alternatives for Melodyne? or a free software that can make the auto-tune effect?