Grammy-winning rapper Macklemore issued an apology Monday night for a costume he wore at a concert in Seattle that prompted angry accusations of anti-Semitism.

The rapper wore an oversized nose, bowl-cut wig and a long beard Friday night while performing his song “Thrift Shop” in a surprise performance at the Experience Music Project Museum.

The Jerusalem Post said Macklemore appeared as a “stereotypical Jew.”

The Forward also criticized his outfit choice, writing, “Really, Macklemore? A big Jewish nose? Subtle.”

MORE: Five facts about Macklemore

Many in social media were less-than-impressed, as well.

One fan called Macklemore an “idiot” for his “racist Jewish stereotype” dress. Another accused him of playing into the “Jews are cheap stereotype,” given the song selection. Yet another weighed in with “Jews are one of the last groups of people it’s ok to mock, with little repercussion.”

Others called Macklemore a hypocrite, with tweets such as “wants respect for gays & hates Jews” and “Same Love, Same Hate: rapper / 9-11 truther Macklemore dresses up as hooked-nose Jew.”

In his apology, which was posted on his website Monday night, Macklemore said he randomly chose the pieces of the costume so he could disguise himself and move around freely during the show. He said it wasn't meant to be a caricature of a Jew.

"I respect all cultures and all people," he wrote. "I would never intentionally put down anybody for the fabric that makes them who they are. I love human beings, love originality, and ... happen to love a weird outfit from time to time."

He said he understood his critics’ point of view.

"I acknowledge how the costume could, within a context of stereotyping, be ascribed to a Jewish caricature," he wrote. "I am here to say that it was not absolutely not my intention, and unfortunately at the time I did not foresee the costume to be viewed in such regard. I'm saddened that this story, or any of my choices, would lead to any form of negativity."

In a postscript, he provided a link to the website of the Anti-Defamation League, which was formed to fight anti-Semitism.

Macklemore, who won two Grammys this year, including Best Rap Album, has long been an advocate for tolerance and equality. He has stood up to support politically charged social issues, including same-sex marriage and anti-bullying movements. His Grammy performance – he sang while Queen Latifah married 34 gay and straight couples – was one of the most talked-about of the night.

But he also came under fire this year when a tweet – “911… Bush knocked down the towers” – surfaced that was written in 2009 on his authorized account.
Macklemore often talks about his devotion to God and his spirituality, but he hasn’t conveyed any specific religious leanings. When a fan on Twitter asked him last month if he was Jewish, he replied: "Nah. Just got hella good homies."

Eric Schiffer of ReputationManagementConsultants.com said whether the outfit intentionally mocked Jews or not, those in the public eye have a moral responsibility to be culturally aware.

“This country has gone a bit far on the PC side, and we do need to laugh at ourselves more,” Schiffer said. “However, to reinforce stereotypes that are denigrating,” and then deny the intent to be humorous, seems to not be appropriate.”

The Associated Press contributed to this report.