One handed electric guitar?

[drone on]

I've seen some rock guitarist and bassists over the years with their plucking hand off the guitar but still playing notes on the fretboard.  Two examples are Eddie Van Halen and Peter Steele from Type O Negative.  Any electric guitarists who can explain how this works?

[APK]

You can hold a fret down with your index finger and pluck the note with one of the others. With electric guitars it doesn't take much of a pluck to get the note sounding, because of the amplification and sensitivity of the pickups. You can also get good stuff by hammering fingers down on frets to get the note. Sliding works well too.  All with one hand.

[Scott M2]

http://youtu.be/yih1gFKSBng

[drone on]

Thanks both.  And I'll check that video.