Yesterday (Dec. 30) was Patti Smith’s 70th birthday, and she celebrated it with a concert at Chicago’s Riviera Theater. Towards the end of the evening, her good friend Michael Stipe showed up with a cake, and led the band and the audience in a chorus of “Happy Birthday” to her.

Naturally, in this era of smartphones and social media, it was captured by a fan and posted to Twitter. Someone else also recorded the encore, where the former R.E.M. frontman returned to sing her “People Have the Power.” Both can be found below.

Last night’s show, which saw her perform her 1975 debut, Horses, in its entirety, and tonight’s concert at the more intimate Park West, is a homecoming for Smith. Although associated with New York and the downtown CBGB scene of the ‘70s, she was born in Chicago on Dec. 30, 1946, and her family moved to Philadelphia shortly thereafter.

Stipe and Smith have been friends for years. He has often spoken of her influence on him. "Until that day, there was truly nothing like the album Horses," he wrote earlier this year. "Even the cover was something of a singular event, a photograph of Patti appearing mannish in a wrinkled white shirt with a sport coat slung over her left shoulder and a horse pin on her collar. Her skinny body and unkempt black hair read attitude. It was strikingly different from the way the music world usually portrayed woman."

Smith duetted with Stipe on “E-bow the Letter” and “Blue,” both of which appeared on R.E.M.’s New Adventures in Hi-Fi, their last record with original drummer Bill Berry. Smith and R.E.M. were both inducted into the Rock and Roll Hall of Fame in 2007. As Rolling Stone notes, his first performance following R.E.M.’s breakup was as an unannounced opening act for Smith at New York’s Webster Hall in 2014.

Watch Patti Smith and Michael Stipe Sing “People Have the Power”

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