Disappearing midi notes

An example… I have a midi track called, let’s say, PIANO. I duplicate the track and assign a different sound, ORGAN. I now have two separate tracks playing the same midi info. When I delete midi notes from the PIANO track, the notes also get deleted from the ORGAN track. How do I make the two tracks independent of each other?
Thanks in advance,
Cubase Artist 10

When you copied the track, you inadvertently created a “Ghost track”. You’ll recognize this by 3 vertical lines near the right sides of the Parts. When a track is “ghosted” what you do to one will occur in the other. This happens when you Opt/Shift drag a part. Skip the Shift and it won’t happen. You’re thinking the Shift key will constrain the dragged copy. In this case, it doesn’t. Common mistake.

Weasel, thanks, YES I do hold the shift key. But never again. Thanks for the quick response.