"There was nothing 'happy' about the tragedy inflicted upon our country on Saturday and no permission was granted for your use of this song for this purpose," states the letter.

President Donald Trump on Saturday played Pharrell Williams' song "Happy" at a Midwest rally hours after the Tree of Life congregation shooting in Pittsburgh — and now the artist is expressing his anger over the decision through a cease and desist letter sent by his lawyer.

"On the day of the mass murder of 11 human beings at the hands of a deranged 'nationalist,' you played his song 'Happy' to a crowd at a political event in Indiana," writes attorney Howard King in the letter. "There was nothing 'happy' about the tragedy inflicted upon our country on Saturday and no permission was granted for your use of this song for this purpose."

King continues to say Williams has not and will not grant Trump permission to publicly perform or otherwise disseminate his music, and claims the use of "Happy" without his consent constitutes both copyright and trademark infringement.

Although the circumstances are gravely different here, this isn't the first time Trump has received a cease and desist from a musician. Steven Tyler has repeatedly protested Trump's use of Aerosmith's music at his events, and others who have made similar complaints include Prince's estate, R.E.M., Queen and the filmmakers of Air Force One.