The submission process for recordings vs. scores is slightly different, hence the separate links. I know that putting the audio section on top would be counter-intuitive and increase clutter. However, it was actually a conscious decision because it draws attention to that section (essentially an ad), so that we can encourage people to submit performances. If we put the section below scores, much fewer people will see it or care about it. We already have a very robust score section, but in order to get the recording submissions to take off I believe we need to give it all we've got.
It is true that scores are the main attraction of IMSLP at the moment. But that's only "at the moment"...

I am actually fairly surprised at how hard it is to get decent quality free recordings of classical music on the net.