THIS is the most brilliant use of the Svengali principle I have ever seen! Thanks to David Garrard for inventing it and Sammy Smith for producing it! Show a sketch pad cut into three parts. Flip through the top third to show different heads-bald, hairy, Elvis, redhead, etc. Have a spectator stop you on one. Repeat with the middle pages to get a face with eyes, ears and nose. Finally, a third person tells you to stop on the chin/mouth page. By using three people, each stopping you at random, you could make a thousand different faces.
So there's your final face, a 3-way composite. That's when you remove a picture from an envelope of the face you saw in a dream last night-and it is EXACTLY the SAME FACE! Complete with gimmicked sketch pad, precision made, extra picture, envelope, and instructions. Wonderful!