At the annual Bridge School benefit concert in Mountain View, California Metallica joined Neil Young on stage for a rendition of Buffalo Springfield's "Mr. Soul."

Young and James Hetfield shared vocal duties on the song's chorus, but Young handled the vocals for the rest of the song.

The most entertaining part of the performance was a bit of a guitar duel between Young and Metallica's Kirk Hammett, as the pair traded solos during an extended instrumental section.

"Mr. Soul" was written by Young for the album Buffalo Springfield Again back in 1967, the band's second studio album.

The benefit concert is held every year in October at the Shoreline Amphitheatre to raise money for the Bridge School.

The school helps physically challenged children to overcome their impairments.