Dark Side of the Moon is 50 years old. A defining album, still futuristic , still poignant, and still being discoverd by fans. The cover is a masterpiece of simplicity, parodied and refereneced and remixed over and over again.
There aren't many examples in popular culture that are quite so universal and ubiquitous, and as time ticks away we get closer to some albums becoming ageless and appreciated by every generation.