I know of a few pitch-shift 'cover's of SU songs that definately make it sound like men are singing rather than women. Same with [@Akayaofthemoon], Jailbreak was my first actual episode watched fully. I have a few friends who have watched the show before, so I knew a little beforehand, but I could have just as easily considered Ruby a man before finding out that they had no genders. 

I could also easily believe that Jasper is the Gem-version of Mulan.