Thanks for the project file.
This is what you need to do to scroll the PNG:
- In the Transform effect on clip in the bin click on the third Alignment button from the right. This will scale the .PNG to fit the project dimensions.
- Switch off the built-in Transform effect on the clip in timeline and add a normal one.
- Scale the clip to the size you want and position it as needed.
- Now you can use the Transform effect on the clip in the timeline to scroll the note sheet using keyframes or whatever.