Macklemore, a Grammy-winning rap artist, found himself at the center of a controversy Friday night when he performed in a costume that some viewed as offensive to Jews.

During a surprise gig at Seattle’s Experience Music Project Museum, Macklemore, whose real name is Ben Haggerty, sang his hit song “Thrift Shop” while wearing a wig, black beard and hooked nose. A getup that, unsurprisingly, many found objectionable.

After the performance, Jewish actor Seth Rogen tweeted, “@macklemore, first you trick people into thinking you’re a rapper, now you trick them into thinking you’re Jewish?”

Macklemore denied that he intended to mock Jews, tweeting that he put on a “fake witches nose” as a “random costume.”

The title of song also led various observers to the conclusion that rapper did in fact intend to reference Jewish stereotypes.

Macklemore is no stranger to controversy.

Tweets of his from 2009 surfaced earlier this year on Buzzfeed, where he appears to blame former US president George W. Bush for the September 11 terrorist attacks.

He has also emerged as an outspoken advocate for same-sex marriage, performing his song “One Love” at the 2014 Grammy Awards while 33 couples were married onstage.