The term "modern art" is really no longer modern being a over 100 years old reference to art that is outside the norm. It really began in France in the late 1800s with artists (like) Van Gogh and continued in the eary 1900s with abstract art. Artist like Picasso, Klee, Kandinsky and many others were "modern". The term seems to have carried into the 1970s. Today acceptable art includes the traditional, portraits, landscapes, etc along wth abstract and installation and performance. Most art is as it is intended, decorative but much recent art for the past 25 years or so is created to make us think, think about our world, environment, etc.