The attraction of Brahms' piano music lies in its own distinct world. His music has not only concrete vigor like the music of Bach or Beethoven, but also the same mildness as found in the music of Chopin. Due to these two qualities, players can sometimes be confused about how to interpret it. This work approaches how Brahms expected musicians to play his music, especially in regard to piano performance practice. The word "aesthetic" in this work translates as beauty, something like the ideal Brahms must have imagined as he tried to portray his ideas in sound. I use the expression "aesthetic in playing" rather than "method of playing" in my title to placeemphasis on a sensibility which, in my view, should always be the underlying consciousness when performing. Although I can hardly claim a comprehensive understanding of his music, I sincerely hope that this work may serve as a guide to all those pianists who love to perform Brahms.