With the year coming to an end, it's time to look back and reflect on all of the music that was released this year. 2015 was a pretty great 12 months for hip-hop. From the beefs to the albums to the new artists making a name for themselves, the genre is everywhere.

Take a look at politics. Hip-hop has also been more involved in the presidential race this year. As the 2016 election gets closer, artists such as Waka Flocka Flame, Nicki Minaj and Pharrell have endorsed candidates. Even Killer Mike introduced presidential candidate Bernie Sanders for a rally in Atlanta.

But the music is the reason for hip-hop's expansion. There were plenty of amazing records that came out this year. Drake's "Hotline Bling" has been omnipresent and been remixed by a ton of artists inside and outside of hip-hop. The video has been mocked by huge names too, including Donald Trump. A lot of new artists released quality projects such as Nef the Pharaoh, Boogie, Raury, Vince Staples, GoldLink, K Camp and Dej Loaf. Hip-hop heavyweights like Kendrick Lamar, Big K.R.I.T., Big Sean, Future and more put out quality albums.

So far we released our list of the best songs and best album covers of 2015. As part of our year-end review, XXL highlights some of our favorite songs that we felt were the most slept-on in 2015. The list includes singles that came and went mostly unnoticed plus deep-cuts we loved off the albums and standalone songs that came out this year. Here are 20 Most Slept-On Songs of 2015.