Legendary pop star Madonna has reportedly begun working on her 12th studio album, according to a Tweet posted by her manager, Guy Oseary.  "It's official.. Madonna's 1st day in the recording studio for the new album... Very exciting.. Happy 4th of july...,"  the blog posting read.  The album will be the singer's first since 2008's "Hard Candy," which has sold 739,000 copies according to Nielsen SoundScan.  No word yet from Madonna's camp on whether a tour will follow the album.