One notable re-entry next week [Billboard Pop Album Chart] might be Fleetwood Mac's "Rumours" album, which is profiting from the power of Fox's "Glee." The TV series dedicated its entire May 3 episode to the 1977 album -- which spent 31 weeks atop the chart. Six of the set's 11 songs were performed by the cast, while another was heard in its original form as background music.