Donald Trump used Prince's music at a campaign rally, and Prince's estate is not happy about it.

Over a year ago, Trump promised Prince's estate that he would not use any of the late artist's music for his campaign events. But yesterday, "Purple Rain" boomed across the crowds as Trump took to the stage in Minneapolis. In response, Prince's estate posted a photo of a letter that confirmed the President's vow to refrain from using the songs.

Prince fans are as outraged as his estate. As the song played in Minneapolis, protests broke out in the theatre across the street from the rally, which is where the song's original music video was filmed. Now Twitter and the Internet are ablaze with anger, though as usual, the President will likely face no consequences for his blatant disregard of the law and all moral decency.

Prince died in April 2016, months before Trump was elected, but one would imagine that the singer—who openly discussed AIDS, criticized the machismo of the space race, supported Black Lives Matter, and relentlessly fought corporate interests in the music industry—wouldn't approve of 45, to say the least.

Using "Purple Rain" is a particularly low blow. The Trump team's decision to play the song is arguably as insensitive as the time the president played Pharrell Williams' "Happy" mere hours after a gunman killed 11 people at a Pittsburgh synagogue.

"Purple Rain" is Prince's number one hit, inextricable from his legacy and persona. It's a song about forgiveness and love and the expansive force that truly great music can be. One needs only to watch the first moments of the song's music video to comprehend the force of the song's meaning; you can see it written all over Prince's face.

Prince - Purple Rain (Official Video)www.youtube.com

On the other hand, Trump—as an entity, a symbol, and a politician—is fundamentally hollow, a cheap mutation of garish American greed and corruption. He never fails to dig his claws deeper into all that seems to mean something in this world, and he never expresses an ounce of remorse or empathy.

Using "Purple Rain" in a campaign rally is far from the worst thing Trump has done—encouraging white supremacy and xenophobia, imprisoning innocent children, and denying climate change are contenders for that prize—but it does symbolize something powerful. It also reveals exactly why Trump and music exist in polar opposition to each other. Music is about truth, connection, artistry, and empathy, all of which Trump lacks the ability to understand.

What makes Trump so incompatible with music? Perhaps it's that Trump as an entity is essentially atonal and dissonant. There's no harmony to his way of operating, no beat or rhythm or reason to the spaces he and his administration and supporters occupy. There's no emotional consistency and no resonance to his existence. He stands in opposition to everything that music is and all that musicians tend to stand for (unless you're Kid Rock or Kanye West, tragically). It can't be a coincidence that in The Art of the Deal, he wrote that in second grade, "I punched my music teacher because I didn't think he knew anything about music and I almost got expelled."

Is anyone surprised that this man doesn't respect Prince's legacy enough to refrain from using his work against his will? Has Trump ever granted anyone that decency?

In general, musicians want nothing to do with the president. Who could forget the struggle he underwent to garner support for his inauguration, and everything that's happened since? Just this week, in her Vogue cover story, Rihanna attacked Trump in a discussion about gun violence in America. She said, "Put an Arab man with that same weapon in that same Walmart and there is no way that Trump would sit there and address it publicly as a mental health problem. The most mentally ill human being in America right now seems to be the president."

So many other musicians have asked Trump not to use their music that it would be impossible to list them all here. Adele, Elton John, R.E.M., Pharell Williams, Axl Rose, The Rolling Stones, and many more have told him to keep his paws off their work, and hundreds of others have denounced him in their music and personal statements.

Even if Trump did possess an atom of musicality or knew how to listen to a sound other than the grating industrial noise that certainly fills his own brain, "Purple Rain" would be a strange song choice to use for a campaign rally. When describing the song, Prince said that "'Purple Rain' pertains to the end of the world and being with the one you love and letting your faith/god guide you through the purple rain." In another song, "1999," he associated a purple sky with a kind of final apocalyptic revelation, singing, "Could have sworn it was Judgment Day, the sky was all purple."

It sometimes does seem that Trump is a steward of some kind of apocalypse, indicative of some sort of breaking point. It's likely that his rise represents a rupture in American democracy as we know it, marking a final ending to what we knew and the beginning of something else. This could be a very positive thing, if the anger he's churned up carves out space for new visions of justice and equity in the form of the downfall of corrupt corporate interests, or it could mark our further descent into the end times. Either way, none of this makes Trump's use of "Purple Rain" any less troubling. All we can hope for is that Trump and all he stands for faces Judgment Day sooner rather than later.