In 1980, Junko Yagami（八神純子） came up with this funky dynamic number as a love letter to New York City. Yagami had become known for her soaring ballads and Latin-tinged songs, but "Purpletown" takes it straight to the discos. The synths and the guitar don't let you down for a second.
Released in July 1980, her 9th career single peaked at No. 2 on the Oricon weeklies and finished the year as the 19th-ranked single of the year. Yagami made her first appearance on the 1980 Kohaku Utagassen, and it became the campaign song for JALPAK, a group tour service under the Japan Air Lines banner. Apparently, it also became the name for a shopping mall in Kurayoshi City, Tottori Prefecture（鳥取県倉吉市）in 1981 with Yagami's hit as the official song. It just celebrated its 30th anniversary in 2011. No word whether the singer actually visited it. By the way, while Yagami took care of the composition of the song, Yoshiko Miura（三浦徳子) wrote the lyrics, and the arrangement was done by one Masaaki Ohmura（大村雅朗）.
Well, let's bring things up to 2016, shall we? I was just browsing around YouTube last night when I came across one of my favourite AOR ballads ever, "Tonight, Tonight" by Bill Champlin from 1981. I found out that this was actually the cover version of the originally titled "My Everlasting Love" by the late Ray Kennedy when I'd assumed it was the other way around (I also have his version on a compilation somewhere).
Then, I saw off to the side another video with Kennedy titled "You Oughta Know By Now" which sparked a few engrams of memory, but things didn't quite coalesce. Then, I listened to the song, and I just went "Wait a minute! That's 'Purpletown'." Or at least a significant part of it was.
That teaches me to read things more closely. I found out through the J-Wiki article for "Purpletown" that there was some awkwardness, which wasn't clearly answered in the article, as to who wrote the song first. But as the folks on "Sesame Street" often exhort, apparently Yagami's representing office, Yamaha Music Foundation and Kennedy's people cooperated, so that the singer now shares composing credit with Kennedy, Jack Conrad and David Foster. So now I realize that the "You Oughta Know By Now" subtitle isn't just a Yagami addition but a sign of their cooperation (or detente).