Intermezzo op. 119
It goes without saying that Brahms wrote a lot of piano music, from his very first published work to some of his latest opus numbers composed in 1893. His Intermezzo in B minor is an amazing piece of music and quite advanced in harmonic usage. Notice, as but one example, how the very opening measures with the descending thirds create wonderful 9th chords that almost sound like we are listening to Debussy (coincidentally, this work was composed in the same year as Debussy’s String Quartet and one year before Prelude to the Afternoon of a Faun.) I suggest listening with the score that is provided here!
BONUS: Have a look at the score! Fascinating harmony!