The Foo Fighters' Dave Grohl made a surprise appearance during the Harley-Davidson anniversary celebration in Milwaukee.
He played with self-proclaimed "`70s dirt rock cover band" Chevy Metal Thursday evening.
The Milwaukee Journal Sentinel reports he joked he was there because Chevy Metal needed someone who liked to talk a lot between songs.
In reality, Metal drummer and vocalist, Taylor Hawkins, is the Foo Fighters drummer.
Their songs included Van Halen's "Panama" and the Rolling Stones' "Miss You."
Another famous rocker, Joan Jett, watched the performance.
Grohl also had posted on his Facebook page earlier Thursday that he was in town.
More than 100,000 people from around the globe were expected to take part in weekend concerts, parade, street parties and other events celebrating the Milwaukee company's 110th anniversary.