Pharrell Williams doesn’t want anything to do with Donald Trump or his insensitive reaction to 11 Jewish worshippers losing their lives this past weekend during a synagogue shooting in Pittsburgh.

Just hours after the hate crime took place, 45 was spotted at a Midwest rally playing Williams’ Grammy Award-winning song “Happy,” infuriating the Virginia producer. In response, Williams has threatened to take legal action against Trump if he ever uses a song from his catalog again.

“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,” attorney Howard King wrote 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.

“Pharrell has not, and will not, grant you permission to publicly perform or otherwise broadcast or disseminate any of his music.”

Pharrell is far from the first musician to ban Trump from playing his music at rallies. The Guardian reports Adele, Neil Young, the Rolling Stones and Queen have all forbidden the president from using their work.

On Saturday, in what Pittsburgh Mayor Bill Peduto called the city’s “darkest hour,” a man went into the Tree of Life Synagogue and killed worshippers during Sabbath prayer while making anti-Semitic comments such as “All Jews must die.” Robert Bowers is accused of the killings.

The massacre was the deadliest attack in American history on the country’s Jewish community, according to the Anti-Defamation League and Jewish Council for Public Affairs, writes CNN.