Why is a particular measure of Rach Prelude in C# minor always played slowly?

Question

I've noticed that in many renditions of Rachmaninov's Prelude in C# Minor (Op. 3 No. 2) that the fourth measure of the Agitato section is always played in a slow, unusual (almost weird) fashion. You can hear what I'm talking about here:

Video

I normally play that part the same speed as the rest of the section, just quieter (since it says "dim.") but many famous performers do not. Is this something originated by Rachmaninov in his live performances that others just stuck with? What is the correct way to play that?

Answer 1

You did notice that the performance you linked is by Rachmaninov himself, right? He plays the other parts with quite a free tempo, too. In this particular point it's natural to take back because of the diminuendo and end of phrase. Making the melody triplets+thirds work might also be hard in faster tempo. It also contrasts measure 8 where it's natural to go a little forward. Finally the Agitato marking just allows some instability in tempo. So, there you have some reasons to play it like this. Still, there's no correct way so if you can make it work without slowing down, you can do that, too.