Contract to use hall for concert, but hall burnt down before concert
If contract performance depends on the continued existence of a person or thing, and that person or thing ceases to exist, w/o fault of either party, performance may be excused for impossibility of performance
The contract was not an absolute K, but rather subject to an implied condition that the party shall be excused in a case where before performance becomes possible the subject matter of the K has perished, w/o fault of either party to the K.
If the nature of the contract is such that the parties must have known at the time of contracting that it could not be fulfilled unless some specified thing continued to exist, it is not a positive contract
**However, if a party gives an express or implied condition that that thing will continue to exist, that party is liable for breach if it ceases to exist
Parties contracted on the basis of the ongoing existence of the music hall