Again, I’d agree with you observations. I think bass is a bit low in the mix on quite a few session, (Contours for example), and often piano has a shut in slightly muted sound, like the lid is down. Others have commented on this, but I don’t know of any particular investigation or conclusion. It could be that it wasn’t such a great sounding piano.
To my ears Van Gelder was great at capturing the energy and spontaneity of a session, especially drums, even though the sound balance and tonality could often be a bit wayward in comparison to someone like Teo Macero. But then we are talking about completely different scenarios and aesthetics.
I think it is all down to Van Gelder's recorded preferences. I have commented on it a few times on these releases and I think the excellent mastering and pressing quality of these issues that were meant to reproduce as far as possible what was on the mastertape hi-light more of Van Gelder's recording methods and preferences. Since commenting here I have seen many others have commented on his piano sound even back to the original releases.
Clearly as you say he loves capturing the energy of a session and close mikes to spotlight Reeds & Brass soloists to do this. He is also excellent with drums where he gets both the weight and dynamics of the kit, and I have never heard it better than on these reissues, as well as the delicacy and 'air' around brushed cymbals. With piano though in most cases I get the feeling he Is just has one mike above the keyboard and not much under the lid. Could be the lid is down? You then don't get much of the body (weight and size of the instrument) or its decay. Plus for some reason he keeps the piano a bit down in the mix. My conclusion was he doesn't like piano players.
It seems though when the Piano players are also the leader on the session they usually get much better, if not perfect treatment. Perhaps Alfred Lion or the leader were a bit more insistent then. What I have never done and might be interesting is to directly compare the piano sound when he recorded at his parents home in Hackensack to the later Engelwood recordings to see if this has any bearing one way or the other?
Edit: I have just remberbered this post on London Jazz Collector about Van Gelder's recording methods that has had input by Kevin Gray:
https://londonjazzcollector.wordpre...cords-and-the-transition-from-mono-to-stereo/
Nothing specific about his recording of piano, but the move from mono to stereo and change of recording studio may have a bearing.
I have always thought Van Gelder's recordings were very much left right with very little centre fill and quiet often have preferred the mono even when a stereo was available. Even when just recording mono he had already moved bass and piano to the centre for disk cutting reasons and this became essential for Stereo. Another reason for level keeping them down in the mix, because of the amount of groove space their frequencies take up. I think Kevin Gray has said elsewhere with regard to the Tone Poets that one thing they were able to do much was to have a better bass level due to better cutting techniques now available, but they did not alter Rudy's instrumental balance.
Also note that when he moved to Stereo he was still monitoring in mono possibly even when he had Stereo playback at Englewood until 1962. The piano and bass now still in the middle. Along with piano I tend to think Van Gelder's Bass also tends to be weak unless he brings it up in the mix on a solo, sometimes very obviously. Remember Rudy mixed live to the tape so he had little ability to change the balance later. I think perhaps monitoring them in mono when recording makes them seem more forward in the mix than in the final Stereo release.
OK a lot of speculation on my part. I just need a very good Mono and Stereo pressing of the same release to investigate further.
I have a couple where I have both including Blue Train, but with big differences in the pressing and mastering quality.