* The release of The Beatles' Sgt. Pepper's Lonely Hearts Club Band in 1967, which is often considered to be one of the greatest albums of all time.
* The rise of hip hop in the 1970s, which has since become one of the most popular genres of music in the world.
* The emergence of electronic dance music (EDM) in the 1990s, which has revolutionized the way music is produced and consumed.
Musical milestones are significant because they represent moments of innovation and change in the history of music. They often pave the way for new developments and inspire future generations of musicians.