Question about "Dawn of the Planet of the Apes" trailer

What was that screech/crack sound? 'Cause whatever it is, I just fell in love with it. I've never heard anything even remotely like it before. Is it an instrument or nails on a chalkboard or what?

How should we know?

@herokiller12344: I heard that music before, but Idk what they used to create it. Some google search might help you find the answer