Tracks uploaded to someone else's projects are added as Idea Tracks.  This is a special designation that indicates that the file is not yet officially part of the collaboration.  The owner of the collaboration will be notified and will do one of three things:

1. Accept the idea into the collaboration, or
2. Archive the idea track, or
3. The owner of the collaboration will do nothing.

Option 3 is greatly discouraged, and there are features built into Kompoz to try to prevent that.  Most likely, the owner will accept or archive the idea track, and add a comment to provide feedback.  

If your idea track is accepted, then you will be added as a participant (collaborator) within the project automatically.  The project will appear in your Collaborations Joined list within your workspace.  

You can keep track of all pending ideas from your workspace page.