Signing you in

Washington - A majority of the artists who were announced as performers for what's being billed as a Great American State Fair amid President Trump's push for a major American birthday bash this summer in Washington, D.C., dropped out of their appearances shortly after an initial lineup was released.

On Wednesday, Freedom 250, a bipartisan nonprofit established to celebrate the country's 250th anniversary in the nation's capital, announced the initial set of artists lined up to perform. But by Wednesday night, two artists had already backed out of or turned down the opportunity, and several more followed on Thursday.

The Commodores, also originally announced as performers, said on social media Thursday the group "will not be performing at the Great American State Fair."

"Our music has always been our voice and we choose not to publicly affiliate with any single political party," the statement said. "We support the betterment of all Americans."

Country singer Martina McBride announced on social media she will not perform. She wrote that she initially signed on because she was told the event would be nonpartisan, which "turned out to be misleading."

"I asked lots of questions and was assured this was a nonpartisan event that was meant to celebrate ALL 50 states," McBride wrote Thursday. "Yesterday things started changing and what we were told is, in fact, not what is happening."

Bret Michaels, of the band Poison, said on social media that he won't be there.

"Unfortunately, what was presented to us as a celebration of our country has evolved into something much more divisive than what I agreed to be a part of," he said. "Concerns have also been raised regarding the safety of my fans, band, crew, family and myself, including threats that are completely unfounded and unforgivable."

Although half of the front-facing Milli Vanilli pop duo, Rob Pilatus, died in 1998, Fab Morvan, the other half of the duo, said he'll be performing.

"Despite any rumors out there, I will be performing at The Great American State Fair in Washington, D.C. at the National Mall on June 26th, as a part of The I Love The 90's Tour," Morvan said in a statement to CBS News. "I am here to entertain and unite people, not divide them. Let's celebrate life & music and take a trip down memory lane. I feel honored to be a part of the Great American State Fair as it will celebrate the 250 Year Anniversary of America with so many other accomplished artists. Looking forward to reconnecting with you across the USA this summer and to finally sing Milli Vanilli songs live in person!"

Vanilla Ice, who is also part of the initial lineup, still plans to perform. "Vanilla Ice is contracted and will perform at the Great American Fair at the National Mall on Friday, June 26," his management agency told CBS News in an email. "He is proud to help celebrate America's 250th Anniversary! Everyone is welcome to attend and celebrate USA's Birthday and our Freedom!"

In a lengthy video posted to C+C Music Factory's Instagram page, band member Freedom Williams said that although he does not support Mr. Trump, he still plans to perform at the event.

Freedom 250 said the initiative is nonpartisan, and should be treated as such.

"Freedom 250 is a nonpartisan 501(c)(3) dedicated to uniting Americans around the nation's 250th anniversary," Freedom 250 spokesperson Rachel Reisner said. "Freedom 250 is focused on our signature celebrations and events that honor our history and engage all Americans - welcoming all who share our goal of commemorating this milestone in a way that uplifts and unites America."

Freedom 250 commissioners include both Republican and Democratic members of Congress. Mr. Trump has expanded on the 250th celebrations, although they were in the works before he became president.

The Great American State Fair, according to Freedom 250, will feature all states and territories in a world fair-style celebration, including exhibits, showcases and cultural programming from the U.S. Capitol to the Washington Monument. Mainstage musical performances are expected every Thursday, Friday and Saturday night.

Some America 250th concert artists drop out Multiple artists announced for America's 250th anniversary concert drop out 00:28 Multiple artists announced for America's 250th anniversary concert drop out (00:28)