The Soweto Gospel Choir had scheduled a performance of James Brown's I Feel Good last weekend, but when Nelson Mandela died on Dec. 5 at age 95, their plans changed.

Dressed as employees at a Woolworths grocery store in Pretoria, members of the choir surprised shoppers with a stirring rendition of Asimbonanga, a Mandela tribute song from 1987 by musician Johnny Clegg.

Click the video above to watch the performance. On mobile? Click here.