Hi Trident,
actually I'd thought about doing something along those lines, but instead of silence, put in a sound like a whistle or squeal to alert me that I'm using a new instrument that I'll need to add to my font.

The font is sort of a work in progress. I'm going to start with 1 style, find the 6 or so most suitable instruments required ( from the various fonts) then go onto the next style ( add any additional instruments) etc etc and slowly build the font up. Having some sort of an "alarm bell" to alert me when I need to add an additional instrument will come in handy ( be it a whistle sound or whatever , as long as it's small) . Personally I doubt I'd probably use more than 30 or 40 different instruments throughout the styles, so it will be interesting to see if it works.

best wishes
Rikki