Guns and Roses, Chicago, 19th Devember 1987. (Photo by Paul Natkin/WireImage)

Pretenders’ singer Chrissie Hynde joined Guns N’ Roses on stage Monday night (August 21) at Fenway Park in Boston to add harmonica to “Bad Obsession”.

The bands are touring North America together. The GNR tour visits historic venues across the country such as Wrigley Field in Chicago on August 24.

Pretenders will release their new album, Relentless, on September 1.