Rachmaninoff himself wrote two cadenzas for this concerto. The one I listened two was in a chordal style, its also known as the “ossia” – cadenza. Its length is roughly three and a half minutes.
If there are a few notes, that are being placed on their own, they were barely noticeable. The whole cadenza provides a feeling of tension, due to it being rather fast and hectic combined with mostly dissonant chords. At the very beginning, it seems, that the lower voice (left hand) plays a very deep pitched melody whilst the right hand accompanies with chords. There are parts, were , the changes between high and low pitched notes happen rather slowly, for those the melody leads its way up and down. Within a sequence in the middle, this motif changes to quick jumps from low pitched chords, to very high ones.The last few seconds of the cadenza seem to be the only ones, which seem a bit calmer than the rest.
I personally didn’t like the hectic of this cadenza, especially because it didn’t fit well to the concerto, which generally seems a bit calmer. All the dissonant chords made it difficult to find any structure, after having listened to it the first time it just seemed like a random mix of notes to me, with slight aspects of the main theme getting involved. Also, quite interestingly, and maybe due to the fact, that Rachmaninoff worked with a few pentatonic scales, I had the feeling the cadenza had a “Asian”- (and very aggressive) sounding character.