kslider bug
This is something that is either relatively new (since max 5) or has been around for yonks, and no one's noticed.
The kslider sends out the wrong MIDI pitch number when pressed by mouse click in the top right region of the highest key (at least when it's a D, probably when it's other notes, but haven't checked).
Max Patch
Copy patch and select New From Clipboard in Max.
This happens on windows & mac with max v5 and mac with max v6.
ghost black keys :)
just bumping this-- response from c74 please