work against the unauthorized public representation of translations of their works.
In order to enjoy the protection of the present Article, authors shall not be bound in publishing their works to forbid the public representation or performance thereof.
Article 12.
The following shall be specially included among the unlawful reproductions to which the present Convention applies: Unauthorized indirect appropriations of a literary or artistic work, such as adaptations, musical arrangements, transformations of a novel, tale, or piece of poetry into a dramatic piece and vice versa, &c., when they are only the reproduction of that work, in the same form or in another form, without essential alterations, additions, or abridgments, and do not present the character of a new original work.
Article 13.
The authors of musical works shall have the exclusive right of authorizing (1) the adaptation of those works to instruments which can reproduce them mechanically; (2) the public performance of the said works by means of these instruments.
Reservations and conditions relating to the application of this Article may be determined by the domestic legislation of each country in so far as it is concerned; but the effect, of any such reservations and conditions will be strictly limited to the country which has put them in force.
The provisions of paragraph 1 shall not be retroactive, and consequently shall not be applicable in any country of the Union to works which have been lawfully adapted in that country to mechanical instruments before the coming into force of the present Convention.
Adaptations made in virtue of paragraphs 2 and 3 of the present Article, and imported without the authority of the interested parties into a country where they would not be lawful, shall be liable to seizure in that country.
