In an interesting article on Ratter.com, Parker Higgins dissects the lawsuit by the Marvin Gaye family against artists Robin Thicke and Pharrell Williams claiming their song Blurred Lines unlawfully copies Gaye's Got To Give It Up. The title Blurred Lines is dubiously appropriate, as that is exactly the conundrum here. At what point does inspiration become theft? The line certainly is blurry.
The basic question has become, are the non-melodic environs of the song protected by copyright? Is a particular distortion of an electric guitar copyrightable? Is the use of a cowbell? Is singing in an alto vocal range?
As Higgins points out in the article, "When we say a song "sounds like" a certain era, it's because artists in that era were doing a lot of the same things — or, yes, copying each other. If copyright were to extend out past things like the melody to really cover the other parts that make up the "feel" of a song, there's no way an era, or a city, or a movement could have a certain sound. Without that, we lose the next disco, the next Motown, the next batch of protest songs."
Direct inspiration of this nature is nothing new in architecture. How different would New York feel without its brownstones? Paris without its Mansard roofs? San Francisco without its bay windows? Or New Orleans without its shotgun houses? These common elements in architecture are what give a city its sense of place. Without that, these cities might be a haphazard mix of unrelated elements. Is this stealing, or simply being influenced by your neighbor's successful design?
The state of current design is a reflection of our collective history of learning about design. This applies to all things, knowledge is built upon generation after generation. It is a blurred line, when exactly inspiration crosses over into downright theft of a unique idea. Where that line falls will likely vary depending on who you ask. The intellectual property of artists and thinkers needs to be protected, in a world that values it less and less. However, we shouldn't let that line cross over into a place that prevents our ability to learn from each other.