A major concert series celebrating America’s 250th anniversary has seen a growing number of performers withdraw from the event after threats emerged against artists who agreed to perform, following months of criticism from President Donald Trump’s critics in politics and entertainment.

Poison singer Bret Michaels announced his decision to exit the 16-day festival, which runs from June 25 to July 10, citing threats against himself, his fans, and family. In an Instagram post early Friday, Michaels stated that what was initially described as a celebration of the nation through music had “evolved into something much more divisive.” He added concerns about safety for his band, crew, and loved ones, including unfounded threats he deemed “completely unforgivable.”

Michaels joins several other artists who have recently withdrawn from the event. Country singer Martina McBride also confirmed her departure, while Morris Day, Young MC, The Commodores, and Fab Morvan (of Milli Vanilli) have announced they will not perform.

Only two acts among nine scheduled performers—Vanilla Ice and Fab Morvan—are expected to proceed with their appearances. C&C Music Factory’s Freedom Williams has expressed uncertainty about his participation.