Watch Foo Fighters Debut New Song "The Sky Is A Neighborhood"

Last night, Sammy Hagar and James Hetfield held their annual Acoustic-4-A-Cure benefit at San Francisco's Fillmore, raising money for UCSF Benioff Children's Hospital and its pediatric cancer research. Foo Fighters frontman Dave Grohl was one of the acts on the bill. And during his acoustic performance, he and Foos drummer Taylor Hawkins debuted a new…