It has long been a running joke that if you only know how to play the G, C and D chords on a guitar, then you already know how to play hundreds of different popular songs. Many musical acts have been ridiculed for only playing the same three chords over and over. “Three-chord” rock music is practically its own genre. The I-IV-V major key chord progression is even considered the “standard” blues progression. Within that construct, there are only 12 basic “notes” or tones in the musical spectrum: A, Bb, B, C, C#, D, Eb, E, F, F#, G, and G#. From there it is just a matter of octaves to achieve different ranges of an “A” note. In short, there is a finite amount of discrete notes along with a relatively limited amount of chord progressions that are available to a songwriter.
Copyright law, meanwhile, only protects “original works of authorship” in musical works and sound recordings. It is right there in the statute: the song or sound recording must be original. Without the element of originality, there is nothing protectable under the law.
Knowing this, and with hundreds of years of the history of songwriting, are there any songs that are truly “original” anymore? Is there any progression or riff that is so unique as to stand apart from every song that has been previously written? If not, how are musical works still subject to claims of copyright infringement and why should we care?