Macklemore gave a surprise performance at the Experience Music Project museum in Seattle on Friday night.
But, for some fans, what was even more surprising was the costume he chose to wear on stage, which included a large prosthetic nose, a black wig and a fake beard.
Many folks subsequently lashed out on Twitter, saying the costume evoked Jewish stereotypes.
Soon after the outcry, Macklemore offered up a tweet of his own.
"A fake witches nose, wig, and beard = random costume," he wrote. "Not my idea of a stereotype of anybody."
Macklemore made headlines of a much different sort in January, when he and music partner Ryan Lewis teamed up with the USA Network for an anti-bullying PSA for USA Characters Unite. The video was set to the Grammy-winning duo's moving song "Same Love."
"We intended ‘Same Love' to help spread a message of love, tolerance and acceptance and we are proud to align ourselves with the Characters Unite movement which shares the same goal," Macklemore and Ryan Lewis told E! News in an exclusive statement at the time. "Through the new Characters Unite PSA, we hope to inspire even more people to take part in such an important cause."