The Foo Fighters played a secret show (under the name "The Holy Shits") earlier this week at the Islington Assembly Hall in London. They also secretly debuted an instrumental version of one of their brand new songs. Check it out here.The new tune, called 'Outside', will be featured on their forthcoming album, Sonic Highways, due out on November 10. They didn’t just play the song outright at Islington Assembly Hall - they stuck it in the middle of ‘The Pretender’. Here's the video (the new track is first revealed around the 2:07 mark):