When relying on agreements in which creators transfer rights to a hiring party (Copyright transfer agreement), a hiring party often finds that it has only limited scope to alter, update, or transform the work. For example, a motion picture may hire dozens of creators of copyrightable works (e.g., music scores, scripts, sets, sound effects, costumes) any one of which would require repeated agreements with the creators if conditions for showing the film or creating derivatives of it changed. Failing to reach agreement with any one creator could prevent the showing of the film entirely.