The 24th of March marked the 40th anniversary of The Dark Side Of The Moon. For a Couple of weeks (starting from the 10th of March) Pink Floyd posted the famous prisms separately on the net.
Only on 23th of March has been revealed what it was all about.
It is a creative poster from the graphic designer, recently died, Storm Thorgerson (Storm Studious).
You can easly download it on the Official Pink Floyd.
Here below you can even give ear to the Pink Floyd’s Masterpiece: