In theory, there may be some jurisdictions that do not allow tapes to be 
admissable because of issues other than relevance--such as authenticity. It 
is hard to know the Evidence Rules of every jurisdiction. I would suggest the 
following language:

The parties to this Agreement agree that any such recording are admissable in 
any legal proceeding for any matters relevant to the Agreement, except for 
those recordings that violate the Parole Evidence Rule of the applicable 
jurisdiction.