Your post made me recall of a technique I saw on a mixing book some 30+ years ago. The trick consisted in linking together two or more potentiometer knobs on a

Your post made me recall of a technique I saw on a mixing book some 30+ years ago. The trick consisted in linking together two or more potentiometer knobs on a mixer by using thick rubber bands, so that one could rotate more than one with a single hand, for example to alter a filter while acting on a fx send, etc. By wrapping the rubber band in inverted position on one knob one could also for example pan a sound to left while another one went to the right, etc. This was of course well before automation became widespread. Unfortunately I lent that book to some friend to never get it back, and don't even recall which friend was or the book title.