The Trump campaign struck the wrong chord with the estate of music legend Prince.

The song "Purple Rain" was played at a Trump campaign rally Thursday night in Minneapolis, the city where Prince was born.

The song, which is not in the regular rotation on the campaign's playlist, was played at Thursday's rally before the president took the stage. It was interrupted midway through so that the campaign manager could announce Trump was in the building.

Prince's estate promptly responded to the campaign's use of the song — with documentation.

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 Prince Estate will never give permission to President Trump to use Prince’s songs. pic.twitter.com/FuMUPzSWOe — Prince (@prince) October 11, 2019

In a statement posted on Prince's Twitter account, his estate shared an Oct. 15, 2018, letter in which Trump campaign officials acknowledged receipt of a letter from the singer's representatives requesting they refrain from using Prince's music at any campaign events. The letter promised to abide by the request.

"Without admitting liability, and to avoid any future dispute, we write to confirm that the Campaign will not use Prince's music in connection with its activities going forward," the letter states.

The campaign declined to comment Friday.

During the president's rally at the Target Center on Thursday, Trump brought up the names of some other star musicians, suggesting he did not need the backing of celebrity performers to win in 2016.

"I didn't need Beyoncé and Jay-Z, and I didn't need little Bruce Springsteen and all these people," he said. Beyoncé and Jay-Z performed at a Hillary Clinton rally in early November 2016.

Like Prince's estate, other big-name musicians have asked the Trump campaign not to use their music.

In November 2018, Rihanna signaled she was upset that the campaign played her 2007 single "Don't Stop the Music" at an event.

Not for much longer...me nor my people would ever be at or around one of those tragic rallies, so thanks for the heads up philip! https://t.co/dRgRi06GrJ — Rihanna (@rihanna) November 5, 2018

After it was reported that the song was played at a Trump campaign rally in Chattanooga, Tennessee, the singer replied: “Not for much longer."

"Me nor my people would ever be at or around one of those tragic rallies," the singer said.

Others who have said they objected to having their songs played at Trump campaign rallies include Axl Rose of Guns N'Roses and Aerosmith's Steven Tyler. Tyler has said he doesn't want his music played at any political events.