As I mentioned in that article, I think "Your Song" is the song (their 2nd single) to best represent the duo known as Love Psychedelico. But their debut single "Lady Madonna ~ Yuutsu naru Spider" (Depressed Spider) has got that beat which also fits those unique vocals of Kumi. And I think the guys responsible for the music video must have known that since it looks like it was paying tribute to the late 60s or early 70s. Plus, the underlying rhythm reminded me of the one used to anchor the original version of "Venus" by Shocking Blue which got thrown into huge dance floor popularity in the 80s when it was covered by Bananarama.
The music and words were created by Kumi and Naoki. Not quite sure what those lyrics are all about aside from the fact that they could have been a result of some word association game. But they all sound good coming from Kumi. To add onto the nostalgia, Love Psychedelico's first single was initially available on good ol' primitive audio tape in January 2000 before general release later in April.
As with "Your Song", "Lady Madonna" is also on their BEST album "The Greatest Hits" released in January 2001. The original single ranked in at No. 88.