Brahms''s music always give the listener the feeling of one kind of unpredictable, his work is different from the commonly used phrase rhythm of the strength of configurations, phrases and beat division is not necessarily the same, let the listener creates a feeling of incomprehensible on Brahms''s music.

This report to introduce Brahms''s life and the op.40''s creation background , the beginning is to introduce his musical style and historical position; followed by movement to make music analysis and interpretation .