Contract performance obligation requires parties to perform or offer performance and binds representatives on a promisor's death. Parties to a contract must perform or offer to perform their promises unless performance is dispensed with or excused by this Act or any other law. If a promisor dies before performance, the promisor's representatives are generally bound to perform unless a contrary intention appears in the contract; personal-service promises that are inherently non-transferable cannot be enforced by representatives or the promisee.