E-bow was the instrument you used with a guitar to make that "bag pipe" sound. It sorta strung out the sound with an eerie feel to it. Mike Oldfield used it a few times and a few other groups but it was very hard to master and few guitar players to this day know how to use it with much effect.
Hubby hates them though. Coincidentally, every BC album I had mysteriously disappeared. then he goes and subjects me to Foo Fighter's rendition of Baker Street. Will never forgive them for doing that.