Music scholars consider Richard Wagner as the great German opera composer who transformed Italian opera into an integrated dramatic artwork during nineteenth century. Italian opera, which had dominated the European landscape since 1600s, was highly popular for its focus and primary concern with the human written in conventional and practical way. However, Wagner rejected Italian opera for its libretto, the drama, pretexted music, and virtuoso singing. Wagner called them as “the error of opera,” and hence he felt the necessity to transform the genre. Wagner himself struggled with this problem, but he eventually arrived at a solution considered so revolutionary that it represented not a new kind of opera, but an entirely new genre altogether, the music drama. The goal of this research is to describe and evaluate two specific concepts how Wagner transformed Italian opera into dramatic artwork, and how he was committed to making opera more dramatically realistic with his own inspiration different from the greats of Italian opera. The new concepts include: one unbroken, continuous layout of the drama through leitmotif – underlying motivic idea that unify the whole drama; and the equal role of orchestra to the voice part. Liebestod from Tristan und Isolde is thoroughly analysed as evidence to the author’s arguments.