A Mondrian framework is proposed for exploring the essence of music. In 1920s, Dutch painter P. Mondrian proposed horizontals and verticals as the basic forms of beauty for painting. In 1960s, scientists D. H. Hubel and T. N. Wiesel discovered the corresponding cellular evidences for supporting Mondrian's proposition. Also their achievement helped themselves to win the Nobel Prize in Physiology or Medicine 1981. In this paper, a similar Mondrian framework is applied to exploring the essence of music. It means to interpret the music as the basic forms of beauty for languages. Also traditional neurograms for representing the neural activities within auditory nerves are used as the corresponding evidences for supporting this framework. This new framework also explains why the rhythm, melody, and harmony of a score are so significant in music.