The music of "Don Juan", which Richard Strauss rightly called a "tone poen", is of a double nature: it can just as well be heard as an effervescent and enraptured tour de force of a creative temperament which has found itself or as the depiction of various episodes.
In "Macbeth" it is not the Shakespeare drama which Richard Strauss reproduces here, but rather its essence: a psychogram of the two protagonists in musical terms, a psychic profile of the Scottish nobleman turned criminal usurper and his spouse who ensnares him and spurs him on.
Despite of the manyfold commentaries and philosophical interpretations of "Also sprach Zarathustra" (Thus spake Zarathustra), however, this much is certain that Strauss did not try to set a philosophical system to music. Nevertheless, there is also no doubt that he undertook the task - inspired by intensive study of Nietzsche - of singing the praises of a "superhuman" being in the sense of a spiritual creature conscious of itself and freed of all earthly traces.

Don Juan: Tondichtung nach Nikolaus Lenau für großes Orchester op. 20
Macbeth: Tondichtung für großes Orchester nach Shakespeares Drama op. 23
Also sprach Zarathustra: Tondichtung frei nach Friedrich Nietzsche für großes Orchester op. 30