Lew C. Schon, MD, a foot surgeon to the Foo Fighters' front-man Dave Grohl, performed on stage with the band at Fenway Park in Boston, according to WZLX.
After a broken leg forced Mr. Grohl to cancel European dates, Dr. Schon built a custom-made throne for Mr. Grohl to perform atop with the injury. As an homage, Mr. Grohl performed with Dr. Schon live on stage, with Dr. Schon on lead vocal.
You can view the video here.