Yes I agree, listening to one sing, (who's not the best singer on the block or using the best equipment to produce the sweetest voice), can be a bit fatiguing. I'm considering TC Helicon products but I do have Melodyn which I understand can be used to create harmonies - but I have no idea about harmonies to begin with, I can harmonize the odd bit here and there but nothing solid - so I guess a harmonizer would probably be the best option? Pitty TC Helicon don't sell a software version for a DAW.