Gibbons are a kind of ape - and they sing. If you ever have the opportunity to go to Twycross Zoo, in the English midlands, and stay until closing you will get serenaded by quite the chorus - once one species starts up the rest have to try and drown them out!
Now scientists have discovered that macaques, a kind of money, have a complex enough vocal mechanism to be able to pronounce language in much the same way we can (not the same sounds, but...). Something in their brain gets in the way.
I'd like to point them to gibbons for their next study...to help work out where spoken language actually came from and how we do it.