Linking objects to parents/siblings etc as they are instantiated and deserialised helps. It two objects are related, I link the later objects to earlier objects (in terms of the serialisation/des process). If objects have Next and Prev properties, I make the Prev property set the other object's Next property too.

I might have a problem with notes that have multiple stems depending on the order of the stems.

I just found 'MusicXML'. A WPF app that can open and display scores from this format sounds good for v2.

Finally have all data and fonts packed up in binary stream and compressed. Most of the deserialisation code is written, will start testing it tomorrow.