More than 48 years after it first dropped, Pink Floyd’s “The Dark Side of the Moon” continues to sell, topping 45 million in album sales this week.

Consider the album’s success, it might surprise some people to learn it spent only one week at number one — and that occurred about six weeks after the album was released. Although “The Dark Side of the Moon” has experienced sales boosts over the years — like during eclipses — it’s never even cracked the Top 10 since then.

Despite its popularity, “The Dark Side of the Moon” isn’t even the biggest seller ever. Michael Jackson’s “Thriller” and AC/DC’s “Back in Black” have sold more, according to Billboard.

Is “The Dark Side of the Moon” Pink Floyd’s best album? Why is it so popular?

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