Hi Siegfried, I had this problem, too. There is no button, you have to select (only!) the track you want to work with, go to Edit/Select/All on Selected Tracks. Then go to Audio and choose "Events to Part". Finally, when you double click on your track, it opens in the Part Editor and you can work with the lanes. Unfortunately, when you add new parts, you have to "dissolve parts" and make sure everything in deselected - it might take more than one try. Then you go through the same procedure again. Not ideal. If a more experienced user knows a better way, please help.