The ideal of music-drama, or the art of the future as it was called by Wagner, was that of an art form in which all the arts were woven into one cohesive and continuous line of dramatic expression. Wagner continued the German tradition but developed his own stories, drawing heavily upon German myths and folklore. His libretti were filled with romantic mysticism and supernaturalism, and almost all were concerned with the concept of redemption through love. There were few closed forms, such as recitative and aria. The vocal line became a continuous melody rising out of an orchestral fabric that was also continuous, without usual cadences. The leitmotif unified the sonorous and tension-filled musical texture. The Wagnerian leitmotif was a musical figure that was associated with a particular idea, person, object, mood, or situation. Because Wagner used the orchestra as the main source of dramatic expression, his operas are symphonic in nature. Consequently, it has been possible to have successful concert performances of much of his music without staging or vocal parts.