manipulate [kslider] GUI, perhaps with [coll]

Hey Maxers
I'm building a polyphonic harmonizer/transposer patch, and I've got the guts of it working. The interface uses a [kslider] to choose transpositions (related to original pitch of the file) so that one may harmonise/transpose and otherwise mangle an audio file.

I have limited the polyphony to six voices (an arbitrary choice), and I would like the [kslider] to somehow graphically reflect this limitation; i.e. implement an array or [coll] whereby notes 1 thru 6 will illuminate, but note #7 will switch off note #1, #2 will switch off #3 etc, like a running array type thing. Setting the [kslider] to poly mode created all sorts of confusion, and I looked briefly at [nslider] too without success. The patch is zipped below.

Thanks
Brendan