一番歌：古い快作１(Ichiban uta: Furui Kaisaku 1)

i’ll let wikipedia answer that

Definitions of "city pop" have varied and many of the artists tagged with the genre have played in styles that are significantly different from each other.[2] Yutaka Kimura, an author of numerous books about city pop, defined the genre as "urban pop music for those with urban lifestyles."[8] In 2015, Ryotaro Aoki wrote in The Japan Times:

The term was originally used to describe an offshoot of the emerging Western-influenced "new music" of the 1970s and ’80s. "City pop" referred to the likes of Sugar Babe [ja] and Eiichi Ohtaki, artists who scrubbed out the Japanese influences of their predecessors and introduced the sounds of jazz and R&B — genres said to have an "urban" feel — to their music. ... The term has drifted in and out of the musical lexicon ever since. ... With a term as vague and broad as city pop, it’s natural that no one seems to be agreeing on what the label actually means anymore."[2]
Jon Blistein of Rolling Stone concurred that city pop was "less a strict genre term than a broad vibe classification."[1] According to Japan Archival Series supervisor Yosuke Kitazawa, there "were no restrictions on style or a specific genre that we wanted to convey with these songs" but that it "was music made by city people, for city people."[1] Kitazawa identified two distinct styles that exemplified city pop: "the former a lush, tropical romp, the latter a thumping rug-cutter".[1]

“Pitchfork's Joshua Minsoom Kim called it "a vague descriptor for Japanese music that incorporated jazz and R&B",[4] while PopMatters' Chris Ingalls categorized it as "a type of soft rock/AOR/funk".[9] Wax Poetics' Ed Motta offered, "City Pop is really AOR and soft rock but with some funk and boogie too. Because when you hear funkier City Pop tunes, you hear not only the influence, but in some parts they steal from groups like Skyy, BB&Q Band, and those kinda American boogie and funk groups."[3] An Electronic Beats writer characterized city pop as Japan's "answer to synth pop and disco".[5]”