BeyonceBeyonce is slowing it down on her new single, 'Best Thing I Never Had.' It's certainly a contrast to the first track, 'Run the World (Girls)' which was the energetic first single from her fourth album, '4.'

The release of 'Best Thing I Never Had' comes as a surprise. Following the video premiere of 'Run the World (Girls)' -- a similar upbeat anthem -- 'End of Time' leaked online, but was quickly overshadowed by Beyonce's 'American Idol' finale performance of '1+1,' a track off '4' that equally showcases BeyBey's powerful diva chops.

"What goes around, comes back around, my baby," Beyonce laments on 'Best Thing I Never Had,' a song about losing someone you unknowingly loved only to realize -- cue title -- they were the best thing you never had.