"Dido and Aeneas" and the descent to the underworld

Henry Purcell created the opera "Dido and Aeneas," a retelling of the tragic love story we read in the Aeneid. This website explains a lot more about the opera, including that it is witches instead of Mercury that reminds Aeneas of his duty to found Rome.
One of the most famous pieces of that opera is what is known as "Dido's Lament" or the aria actually titled "When I am Laid in Earth." Here is a version sung by Hayley Westenra, a more modern artist. A link to the lyrics are in the description beneath the video.
 This link talks a lot more about the common theme of the descent to the underworld in myths. If you don't have the time or inclination to read all of it, here's the gist: the descent to Hades or hell was a step on the journey that led the hero ultimately to enlightenment. The author also talks about the significance of the downward descent, literal in the stories we have been reading, where the Underworld is actually under the crust of the earth. Although hell has always been thought of as at least being partially a torture chamber, the Hades of the Greeks also holds the Elysian fields, their equivalent of Christianity's heaven. The author references several other 'descent' myths, including Gilgamesh and the myth of Orpheus. (This link takes you to another site with two versions of the Orpheus myth.) The author of "The Descent into Hades" discusses the idea of the descent being literally versus otherwise and how it may or may not be the equivalent of a temporary death for the hero. Despite the frequency that trips to the Underworld are mentioned, it was not an easy thing. The author lists a number of rituals that the hero would have to complete in preparation for the journey. In the end, the author states, "The true significance of the descent into Hades is not to be measured by mundane results. These are but stepping-stones on the way to greater goals. The ritual is nothing beyond what it represents; the preparation for initiation is everything. Only when the necessary moral strength and purity have been developed will the required transformation of consciousness safely take place. The final initiation will mark the awakening into divinity which is the potential for all humanity."