Well, that's subjective, isn't it? If you've never heard a song, it's automatically obscure. Still, I'll bet there's a lot of people who have either never heard this song, or don't remember it. There's likely even more who don't realize it actually made it to the top of the pop charts.
What is it?
Star on 45 - The Music Video
This is the very first "Stars on 45" medley. I'll let you peruse the Stars on 45 Wikipedia entry to learn more about that peculiar act. That page, and the song's page, will also reveal to you that the official U.S. title of this medley earns it the honor of the #1 song with the longest title. I suspect this is a record which will never be broken.
I keep mentioning that this was a Number One song. It reached that lofty plateau on the chart for June 20, 1981. What's even more interesting is that it dethroned a certified 1980s classic - Kim Carnes' "Bette Davis Eyes" - to attain its peak position. Carnes had been on top for five weeks when this medley took over the top spot.
However, the Stars on 45 Medley only managed to hang around at Number One for a single week before being toppled by..."Bette Davis Eyes". Yes, Kim Carnes returned to the top slot for another four weeks, cementing her song's place in the 80s Music Mythology. Meanwhile, Stars on 45 sank into obscurity. Quite frankly, I had never heard of it until I became aware of the "Bras on 45" parody!
And by the way, who would've guessed there was actually a music video for this song? That's one I bet doesn't get a lot of airplay on whatever channel actually deigns to still show music videos.