A part is a piece of music or other related data. Parts are contained inside tracks or inside the bay. Parts has common properties, descripted in the arranger features.

Copying/Pasting of a part creates a duplicate. If you want, you can "paste as ghost", which means that any changes to the first part will mirror to the clone.
A part can contain lots of different types of data: In addition, parts can be converted to Video with Visualization.