What do you think the biggest song of 2013 will be?

Nurse your hangover with American Top 40's year-end countdown of the hottest songs of the year.

Ryan Seacrest will play em' back on the Z, starting at 6am on New Year's Day, with an encore play at 2pm for those of you who rang in 2014 too heartily!

Anyone of these tunes could take the top spot, tune in to find out!