Short answers, pulled from the story.
The term pop music first appeared in print during 1926 to describe a piece of music having popular appeal. This usage emerged alongside the industrialization of the 1800s which created an urban middle class with specific tastes and interests.
Pop songs typically run between two and a half minutes and three and a half minutes in length. They rely on simple verse-chorus structures where the chorus serves as the ear-catching repetition mechanism.
Improved microphone designs in the 1940s enabled singers to adopt an intimate vocal style previously impossible. Ten years later inexpensive 45 rpm records revolutionized how pop music reached listeners globally.
Japan produces more music than any country except the United States with most output devoted to Western-style formats. Latin pop rose in US popularity during the 1950s following early rock and roll success by Ritchie Valens.
The music industry began changing as people started downloading files from the internet at the start of the 2000s. Streaming platforms now dominate alongside traditional sales figures for artists like Drake and Olivia Rodrigo.