Picasso was innovative in several way.
I am no art student but, I have always had an affinity for the visual arts, painting and photography, especially.
When I was a kid, I remember seeing Picasso's painting of musicians using what is called cubism; painting objects using geometric shapes, hard lines and curves..It blew my mind.
He also did what Van Gogh did during his "temperamental" period; he used color to express the way he was feeling inside; I believe blue was his prevelant color of use at that time in his career--in Picasso's that is.
His depictions of Harlequin were also very moving to me at such a young age. I remember reading everything I could about Harlequin and drawing him as best I could for years during elemntary school.