Song for Guy chorus synth sound

Question

I'm currently trying to reproduce the sounds of Elton John's Song for Guy as a learning project, and I'm stuck with the wind-like sound that accompanies each chorus (and the third and following repetitions of the initial song motif at the end, before EJ starts to sing).

I have a quite convincing bass, and the strings that accompanies the second part of the chorus to its conclusion are good too, but I can't understand what that sound is. I've tried some white noise with a low-pass filter (with a slight resonance) where an envelope changes the cut-off frequency of the filter along with the chorus' parts and it sounds like it when the frequency is high and the sounds morphs into a kind of hiss. However, when the frequency is lower, this isn't it, and by long. It sounds like some king of chord, but without tonality, only resonance, if you get my clumsy meaning. But what chord, anyway, as it seems to be always in tone with each part of the chorus (or it's the filter doing that)?

How on earth is that sound made?

PS: In addition, I found that my accompaniment lacks depth. As a relative newbie, I added more reverb, but that's not enough, obviously. Is there resources on the web on how to construct studio "wall of sound like" depth? And how one teaches oneself to recreate sounds (I've watched hours of sound design videos, but I'm often stuck when trying to learn how to make a sound from a song that is not exactly what I found in some tutorial)?

Answer 1

High resonance [Q], hi-pass filter sweep.
Likely playing one or more notes of the chord structure as it changes - this will be a significant part of the sound, switching up the inversions & spread of the notes as this section increases in sonic impact. What the sound is underneath would be quite hard to tell, but obviously one with a lot of high frequency in it, perhaps a saw-tooth base. There may be some noise mixed into it, but I'm not really hearing any. I'd guess the sweep was done manually rather than as part of the patch, as the speed changes over time [& is a bit lumpy in places] - one hand for the notes, the other for the filter knob.

The record's release date of 1978 would be perfect for it to have been played on the then newly-released Prophet 5, the first mainstream polyphonic synth.

You can get software imitations of the Prophet these days - notably that by Arturia

Other potential candidates from the time may have been the Yamaha CS-80 or [imo less likely] the Oberheim Poly or the PolyMoog

Answer 2

If you mean the parts like the one starting around...

...I think you want a synth pad.

This seems like a nice tutorial just to get the concept of pads:

But, you can find plugins for pads that are preset with that kind of "sweeping" sound, you don't necessarily need to create your own. Some pads put most of the sweep in the initial sustain then hold one tone, others continuously sweep. You might need to try out several before finding one you like.