Although Kevin Jonas doesn't really sing any main parts in any of The Jonas Brother's songs that doesn't mean he can't actually sing.
So for years I always thought Kevin was just good at guitar and nothing else and that's why he never got his own parts to sing in songs. Turns out dude can actually sing and I think he kinda sounds like a mix of Nick and Joe!
Also some people thinks he sucks but what do they know....
Check out these examples of Kevin actually singing solo