Short answers, pulled from the story.
Tatsuro Yamashita is often called the king of city pop and he was born in 1952. He began his career in the band Sugar Babe which released the album Sugar Babe in 1975. His songwriting and arranging techniques drew heavily from American soft rock bands like Steely Dan and the Doobie Brothers.
New technologies like the Walkman, cars with built-in cassette decks, and FM stereos became ubiquitous during the economic boom of the 1970s and 1980s. Electronic instruments such as the Casio CZ-101, Yamaha CS-80 synthesizers, and the Roland TR-808 drum machine enabled musicians to actualize the sounds in their heads. This tech-fueled economic bubble created a wealthy new leisure class that craved music reflecting their sophisticated lifestyles.
City pop lost its mainstream appeal after the 1980s and was derided by later Japanese generations who grew up with this kind of music. Many Japanese people who grew up with city pop considered it cheesy, mainstream, and disposable, going so far as to call it shitty pop. This rejection was partly due to the genre's association with the economic bubble that burst in the early 1990s.
The song Mayonaka no Door by Miki Matsubara took the No. 1 spot on Spotify's global viral chart for the week of the 10th of December 2020. It broke Apple Music's J-pop top 10 in 92 different markets. This digital resurrection was not limited to Japan and sparked a revival of Indonesia's dormant pop kreatif genre.
Haruomi Hosono a member of the band Yellow Magic Orchestra founded Tin Pan Alley in the mid-1970s. The group fused southern R&B, northern soul, and jazz fusion with Hawaiian and Okinawan tropical flourishes. Hosono's work with the band Tin Pan Alley and his collaborations with other artists helped establish the mixing and arrangement styles that became central to the genre.