muffer - works, but why?

[boog]

so i find the small circuits on Jack Orman's site to be about as useful as Tim Escobedo's when it comes to tinkering; i started playing with the muffer circuit and thought, 'hey, since i don't know why there's a 470k resistor from the base to the collector on the transistor, i'll swap it w/ a 220k resistor and a 250k pot.'  i assumed i would be able to hear an audible change in signal, thus helping further enlighten myself in my quest for knowledge.  incorrect; slight change but not enough to warrent an extra knob.  so tinker tinker tinker and i end up doing 220k resistor to a switchable second resistor, 240k and 10m.  why 10m?  as i was playing with different values i noticed that the higher in value i go, the more 'controfuzz' (mixed dirt and clean signal) i get.  soooooooo.....what is the original resistor for and why do i get that mixed signal when i get the value so high? Link: http://www.muzique.com/schem/muff.gif