The year 2011 is coming to a close and the flurry of retrospectives has begun. The latest to offer a look back is Billboard with its list at the of the Top 20 singles of 2011.

The popular music magazine scoured through the wide variety of music to arrive in 2011 and somehow managed to narrow it down to the best 20. We won't ruin the list for you, but your big names like Adele, Nicki Minaj, and Lady Gaga all made the cut.

Billboard says the 20 songs represent a gorgeous pastiche of veteran artists and talented newbies.

The biggest surprise of the list? Pop superstar Katy Perry is nowhere to be found in the Top 20.

So sit back, relax, plug your headphones in, and listen to Billboard's Top 20 singles of 2011.

Also, feel free to let us know whether you agree or disagree with the Top 20 list in our comments section!