Since Aristophanes and Aristotle up to Romanticism, critics have always been praising the harmony of classical tragedy compared to the modern “philosophical” tragedy, whose disharmony constitutes its very content and form. Euripides expressed the crisis of a long fin de siècle with the crisis of the tragical form itself: the impossibility of an harmonic tragedy is precisely the answer of the less classical among the tragedians of that time. Without rejecting myth, he escaped the established form shaped by his predecessors, thus creating a "new" tragedy, of which Helen is probably the most famous example. As a matter of fact, Helen has received a wide variety of definitions across time such as: «the most entertaining among the tragedies»; «a mere entertainment for the audience»; «everything but a tragedy»; «a good achievement, but without the greatness pertaining to tragedy»; «the greatest among the euripidean tragedies». The aim of my paper is to demonstrate how Helen is actually inserted in a coherent elaboration of the tragic form made by Euripides: it is thanks to the happy ending and to the admission of buffoonish elements within drama – that is to say, by mastering both comedy and tragedy, as suggested by Socrates at the end of the Symposium (223d 3-6) – that the poet managed to be “the most tragic among tragedians”, as Aristotle defined him (Poetics 1453a 30).