After a period in India studying the practice of Transcendental Meditation, the Beatles release their eclectic double album in 1968 titled The White Album.

Nearly four decades later, rapper Jay-Z releases his eighth record, The Black Album in 2003.

In 2004, Danger Mouse releases a mashup album called The Grey Album to critical acclaim. The mashup combined vocal and instrumental tracks from The White Album and The Black Album.  The album does not contain any original sound by Danger Mouse. The music was created by the Beatles and the vocals and lyrics are from Jay-Z.

Despite approval from Jay-Z and the remaining members of the Beatles Paul McCartney and Ringo Starr, the Beatles' record company and copyright holder EMI attempted to stop distribution and sent a cease and desist letter to Danger Mouse and retailers. In response, internet users uploaded digital copies of the mashup album for free. As a result, over 100,000 copies were downloaded and EMI did not take legal action against users despite threats from their cease and desist letters.

What makes The Grey Album different from other mashups is its structure. Traditionally, mashups are a combination of one song played simultaneously with another song. According to Kyle Adams for Music Theory Spectrum, the album is a deconstruction where Danger Mouse "disassembles and reassembles" various sections of the Beatles' music to create a new beat, while Jay-Z's lyrics and vocals remain the same. 

The question that remains is whose interests are protected by copyright laws? From its inception, the laws were meant to protect the artist's rights so that they can stop others from stealing and profiting off their work. Patent laws were created with the intent "to promote the progress of useful art". Despite this intent, it appears that the laws are actively preventing the progress of Danger Mouse's art.

In an interview with MTV regarding the production of the album, the artist described his process: "The first thing the producer did was listen to The Black Album a cappella and measure the amount of beats per minute for each track. Next, he scoured all 30 songs on the “White Album,” listening for every strike of a drum or cymbal when no other instruments or voices were in the mix. Most were single sounds, which he would later put together to make beats. After pulling every possible Ringo Starr part from the “White Album,” Burton repeated the process for guitar and bass samples. Once he felt there was a workable amount of sounds banked, he started with a Jay-Z vocal track and built the music around it." (Adams, 2015)

What makes The Grey Album a progressive art piece is by mashing up two standalone and well-known albums, the artist recontextualizes the two albums' elements by creating new beats out of looped sections of songs culminating in a separate piece of art. 

References:

Adams, K. (2015). What Did Danger Mouse Do? The Grey Album and Musical Composition in Configurable Culture. Music Theory Spectrum, 37(1), 7-24. Retrieved from https://www.jstor.org/stable/90012186