45 years ago this week, Pink Floyd released an album that changed the course of rock history, provided an unofficial soundtrack for “The Wizard of Oz,” and ended up as a poster on every dorm room wall. As “Dark Side of the Moon” celebrates its anniversary, we’re making it available for you to hear on demand as our Greatest Album Ever…This Week.

Justin Bieber has come a long way from his early days as a YouTube phenomenon, teen dream date, and Usher protégée. His first hit single dropped in 2009 and he’s maintained an impressive level of success ever since. We ranked your favorite Bieber songs based on your plays, hearts and shares, and we’re starting this count UP with #1.