The Prince estate said President Trump's campaign broke a promise by playing "Purple Rain" at a rally in the late star's hometown last night, and then posted what it calls proof of that vow on social media.

"President Trump played Prince’s 'Purple Rain' tonight at a campaign event in Minneapolis despite confirming a year ago that the campaign would not use Prince’s music," the estate wrote on Twitter. "The Prince Estate will never give permission to President Trump to use Prince’s songs."

A copy of a letter from an attorney reportedly representing Trump, dated Oct. 15, 2018, was attached to the tweet. It promises "the Campaign will not use Prince's music in connection with activities going forward."

Several other famous acts have criticized Trump for using their music at his campaign events, where the playlists have included such songs as Aerosmith's "Livin' on the Edge," Ozzy Osbourne's "Crazy Train" and Twisted Sister's "We're Not Gonna Take It."

Trump's policies have also come under fire from a number of prominent musicians. Most recently, Rolling Stones frontman Mick Jagger attacked the president's environmental record. "We are in a very difficult situation at the moment," the singer declared. "The U.S., which should be the world leader in environmental control, has lost that and has decided to go the other way.”

Prince referenced the future president by name in "Donald Trump (Black Version)," a humorous romantic ballad he wrote for the Time's 1990 reunion album, Pandemonium. Upon learning of the musician's death in April 2016, then-candidate Trump issued a statement declaring, "I met Prince on numerous occasions. He was an amazing talent and wonderful guy. He will be greatly missed!"

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