Because ours does.
István, a Király (István, the King) opened in 1983, and it has been staged and filmed in countless versions ever since (I kid you not, my high school even had a showcase of it starring our vice principal and our English teacher). It tells the story of our very first Christian king, István (Stephen) who founded the Hungarian Kingdom, and was crowned in 1000AD (to make it easy for students in the future).
The story, historically, actually starts with István's father, Chief Géza. While he had no intention converting to Catholicism, he recognized early that the Hungarians needed to become a Christian kingdom in order to survive in Europe. So he raised his son, Vajk, into the religion, and declared him his heir. This was, however, the way Christian European kings did things, and not the way pagan Hungarians did. Eastern nomadic people often inherit power according to a different system: The closest adult male relative, the strongest possible candidate, follows the chief in power, not the eldest son. This left the Hungarians in a weird situation after the death of Géza: Some of them sided with Vajk (baptized as István) and his Western Christian entourage (courtesy of his German wife), while some of them sided with Koppány, his oldest male relative, who was not only not Catholic, but also claimed the wife of Chief Géza, Sarolt, István's mother, as his wife, according to tradition.
And the rest is war. And a lot of singing.
Koppány (spoilers) lost in the end. His lands were given to the church, he himself was cut into four pieces and nailed to the gates of four prominent cities in the kingdom. Hungary became a Catholic kingdom, István became King István I, and then they sang some more.
Koppány in the rock opera is not a decidedly bad character, however. He is presented as decadent (three wives, huh), but a leader who wants his people to be free from the Church. Over and over again his main song (with the chorus "Fly, bird of freedom") has been used in political ways to promote Hungarian national sentiment. And rock and roll. Also, the guy playing Koppány used to look like Khal Drogo, back in the '80s... Observe:
Interestingly enough, the story addresses the fact that they have no real personal hatred for each other; they are just on opposite sides of politics. There is a really cool duet they do when István offers to give up the throne if Koppány agrees to become Roman Catholic (he is officially baptized as Orthodox). The song is aptly titled "It's too late for peace."
The rock opera ends with István's coronation, and a celebratory song.
The latter two of the videos above come from the Csíksomlyó production of the rock opera. That is especially interesting because while Transylvania used to belong to Hungary, now it is part of Romania, so a huge part of the audience shown in the video is Hungarians who live in a foreign country as an ethnic minority. This gave a special meaning and atmosphere to the whole production. I don't think there is another rock opera or musical that has been applied to current political rhetorics as often as this one. But the music is still good.