I don't know how many are reading any of this and if they play the contraption or not, so I try and relate it to guitar. This morning at 6am I found
that the extra knee pedal (#5) on the guitar, which you push up with your knee instead of to the side, will, when holding down the A&B pedal and pushing the knee lever up, give me minor four chord.
To put it in guitar terms, with no pedals or levers used it is like playing a barred E chord where ever you lay the bar across the neck (if you don't hit the wrong strings).
Staying on the same fret and pressing down the A&B pedal is like now playing the double barre "A" chord, giving you the IV chord in that key. So if you are on the third fret say, you are playing a G chord, hit the two pedals and now you are playing a C chord. Now, with the A&B pedal down and one lets up half way on the A pedal, you are flatting the third to get a minor chord, in this case a C minor. It is a pain doing it that way. If you are just a little bit off with the A pedal, the chord is out or tune. When holding down the A&B pedal it isn't that difficult to let the A pedal up halfway and get it right. To come from any other position or pedal and knee combination to holding the A pedal halfway down and the B pedal all the way down and getting it right is so far, beyond me. This knee lever solves that problem. I guess when you really know your PSG and are a good player you would get it down right eventually. The pedals an levers have stops on them so you don't raise or lower the notes more and you have it set for.