39. Effect of refusal of party to perform promise wholly . – When a party to a contract has refused to perform, or disabled himself from performing, his promise in its entirety, the promisee may put an end to the contract, unless he has signified, by words or conduct, his acquiescence in its continuance. Illustrations (a) A, a singer, enters into a contract with B, the manager of a theatre, to sing at his theatre two nights in every week during the next two months, and B engages to pay her 100 rupees for each night's performance. On the sixth night A willfully absents herself from the theatre. B is at liberty to put an end to the contract. (b) A, a singer, enters into a contract with B, the manager of a theatre, to sing at his theatre two nights in every. Week during the next two months, and B engages to pay her at the rate of 100 rupees for each night. On the sixth night A willfully absents herself. With the assent of B, A sings on the seventh night. B has signified his acquiescence in the continuance of the contract, and cannot now put an end to it, but is entitled to compensation for the damage sustained by him through A's failure to sing on the sixth night. By whom contracts must be performed | 