I have a 60x90 door that I want to sound proof. It is standard pine.

I can treat it on one side without regards to aesthetics but the other side would need to be clean.

Is mass loaded vinyl best?

The swoop at the bottom and weatherstripping on the sides will do alot. Is it a solid wood door?

Yes solid but just pine not some super thick door. I want to find something to put on the door, extra layers or something

can you just build a wall over it? or does it need to open? I'd think anything think would do. I know you can get that lead lined drywall.....

Has to be open.

Thinking mass loaded vinyl and maybe some bass traps but I know almost nothing about this.

http://www.ehow.com/how_2096138_sound-proof-door.html