The document discusses the origins and evolution of the pop-rock music genre. It notes that pop-rock originated in the 1960s in the UK and US, with early artists like The Eagles, Fleetwood Mac, and The Three Dog Night incorporating pop elements into their rock music. Over time, pop-rock has grown in popularity and now includes mainstream artists like Kelly Clarkson, Avril Lavigne, and Maroon 5. While the basic musical conventions have remained the same, including the use of electric guitars and drums, pop-rock has become a more successful and popular genre in the 21st century.