Remember the six dots, in one color, and six dots of which one was in a different color.
Instead of "show" there would be a symbol of all black dots. Instead of the right side of it there would be the symbol of all white except one black dot, and clicking THAT would bring down the dropdown, and then the symbol would disappear but the instrument name would be displayed, and then the "all" symbol would still be to the left and could be activated, and when that is activated the "individual" symbol would appear again. So it would never say "all" but just raise/toggle/activate the "all symbol".
Remember the six dots, in one color, and six dots of which one was in a different color. Instead of "show" there would be a symbol of all black dots. Instead of the right side of it there would be the symbol of all white except one black dot, and clicking THAT would bring down the dropdown, and then the symbol would disappear but the instrument name would be displayed, and then the "all" symbol would still be to the left and could be activated, and when that is activated the "individual" symbol would appear again. So it would never say "all" but just raise/toggle/activate the "all symbol".