Attorneys for Pharrell Williams sent President Donald Trump a cease and desist letter denouncing the use of the artists song Happy at an event Trump headlined on Saturday, mere hours after the deadly mass shooting at a Pittsburgh synagogue.

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, read the letter sent Monday, first reported by The Hollywood Reporter. There was nothing happy about the tragedy inflicted upon our country on Saturday and no permission was granted for your use of this song.

On Saturday, a gunman shot up a Pittsburgh synagogue, killing 11 people in what is likely the deadliest anti-Semitic attack in U.S. history. The suspect , 46-year-old Robert Bowers, had a history of posting racist and anti-Jewish statements online and reportedly yelled during the attack, All Jews must die.

After the attack, Trump called out the evil Anti-Semitic attack as an assault on humanity. Later that day, the president went ahead with plans to attend two events, a Future Farmers of America Convention in Indiana where he joked about having a bad hair day and a rally in Murphysboro, Illinois.

The letter from Pharrells lawyers said the artist has not and will not allow Trump to publicly play any of his music and asked that he cease and desist from any further unauthorized use.

Pharrell isnt the first artist to demand their songs not be played at Trumps events. In 2016, British rock band Queen denounced the Republican National Conventions use of their song We Are the Champions to introduce then-nominee Trump. And earlier this year, Steven Tyler of Aerosmith also sent a letter demanding the president stop playing the bands songs at rallies.