It is just that some of his tunes sound as though he MUST have had an influence from somewhere other than classical music. The 3rd Ballade sounds like there he must have been influenced from popular songs, and especially the etude in E major (Opus 10). I know he was influenced by Polish Dances for his Mazurkas, and even contemplated finding out about Polish folk music, which is not classical music at all! He also mentioned to one of his pupils I think, that his playing sounded more like 'Vaudeville' than whatever else it was supposed to sound like, so he must have gone to Vaudeville, or heard about it.
He liked Bellini.