Ok Grahamee. Let's put it to the test. You will need a blindfold, an assistant, and two or three sax playing friends. You will also need a hat or small bowl, twelve squares of paper, on which six have the word "on" written on them and six the word "off".
1. Get your sax set-up ready to play, and put on the blindfold. Hand your assistant the sax who will add or remove the screw or leave it the same as before based on the draw which is in random order.
2. Your assistant then hands the sax back to you, helps you connect your neck strap and you play a scale, 8 bar phrase, or whatever you like. You then verbally tell your perception to your assistant who makes note of what you said next to "trial 1" along with a code showing if it was on or off.
3. Continue this process until all 12 trials have been completed. Then remove the blindfold then look at the sheet with your comments after each trial and whether the screw was attached or not.
4. A helpful variation of this is to play behind a screen or partition and have your panel of listeners indicate on a sheet of paper whether the sound was the same or different from one trial to the next. This is even better if they don't know what is being done to the saxophone if anything.
5. The listeners can then take turns being the "player" with his/her mouthpiece set-up, and you can rotate to being a listener.
This is a very simple but effective way of removing the "placebo effect" and what I call "the self-fulfilling prophecy based upon expectations" (player believes silver trumpets sound brighter so he/she produces a brighter tone when playing one.) This experiment will reveal:
1. Whether the player has an accurate different "perception" when the mass is added in the neck tenon area, and
2. If so, whether there is a "sonic" difference to the listener several feet away.