Sound dampening

I'll be moving into a new home and will have a dedicated theater. The room is approx 38x15. Unfortunately, the ceiling cannot be raised and is only about 7' high. I am considering covering the walls with commercial draperies retaining the natural pleats. I imagine that I will run curtain rods all around the perimeter to suspend the drapes.

I am thinking about doing it this way to avoid framing and drywalling the space, as after that is complete, I'd still need to sound dampen extensively.

I'd appreciate everyone's thoughts and suggestions. Thanks.