Students are often perplexed by the application of copyright in certain areas of the music industry. For instance, at its core "the blues" shares a persistent three guitar chord progression and similarity of melody throughout the entire genre of music. There is a wealth of internet resources of material for songs that sound like other songs. Sometimes lawsuits are brought and sometimes they are not. I am not an expert in this area of the law, but it seems to me that the distinction rests on the uniqueness of the allegedly copied musical pattern.
Below is a video comparing 6 Country Music songs. As it cleverly and indisputably establishes, they are the same song even to the point of being performed in the same musical key. Despite the song coming from different performers, different studios, different producers, etc. - the song are all one song. The melody is the same, the musical progression is identical, the songs are musically indistinguishable. I expect that the reason why we don't see lawsuits in this genre of music is because there is no unique quality to the music. If you claim a copyright infringement by one artist, there are thousands of others who have the same claim against you. What are your thoughts?