Mike Oldfield demonstrates the Fast Riff from Amarok (audio only) 

Back in 1995 I interviewed Mike in his home studio for his online mailing list. In response to a question about how he played the opening riff to Amarok, he proceeded to grab a guitar and demonstrate.
I can clearly remember being surprised to see that the left-hand fingering was extremely simple, often using just two fingers. All the work was done by the right hand.