Only have certain gameobjects blend but not others in animator

I have two states that I've animated out for a character using unity animation/animator tool. I can control the blending between them, but is it possible to have certain body parts in the hierarchy instantaneously toggle without blending while others do?

ie. I have a sad and a happy animation for a person, blending the two animations has a nice effect on body posture transitions, but the face has features like the mouth, when using the same sprite actually rotates from a frown to a smile throughout the transition. Is there a way to achieve instantaneous rotation while the body blending still remains? Is this something that animation layers can help with?