Red Rock Trivia 12/7

It was this day in Rock History in 2014 this album made a surprise return to the Billboard chart when it landed at No.13, thanks to ultra-cheap pricing in the Google Play store where the album was discounted to 99-cents. What was the album?

Answer:

It was The Dark Side Of The Moon  by Pink Floyd. Although it held the No.1 spot in the US for only a week when released in 1973, it remained in the Billboard album chart for 741 weeks!