An ancient art that originated after God wanted to rock out but had no electric guitar on hand. He realised how sweet a thing he had just created so he wanted to pass it down onto man when man had no axe to rock with. This talent was given to man, by God, through Jesus. Jesus showed the world the ineffable art of air guitar during his ressurection. Jesus was radiating with a bright white light because he was rocking so hard.
The art of the air guitar was thus written down in the Bible and succesfully passed on to man. The practice of air guitar since it's inception has been shown throughout the history of the world. Jesus is discretely air guitaring in the famous painting The Last Supper in the Galleria Borghese, Rome.
On and on has this holy tradition gone. It is kept alive by generations of rockers young and old. If you are listening to a really sweet guitar solo and you have no real guitar to emulate the action of rocking, pick up your hands, put them in position, and rock and roll all night.
Adam was listening to Communication Breakdown by Led Zeppelin and it was nearing the kickass guitar solo. But he had no guitar. So he took matters into his own hands. He played air guitar and never stopped rocking.