Bruno Mars is one of the amazing talents who writes his own songs. He has always killed it in the music industry with some of his biggest hits, "Uptown Funk", "Grenade" and "Locked Out Of Heaven". What you don't see is the hard work he puts in behind the scenes towards the production and writing process of music. He works with Philip Lawrence and Ari Levine as "The Smeezingtons" to create the amazing pop music we listen to today. Check out some of the songs that you had no idea Bruno Mars was a co-writer on.