how to make a track sit in the back

Everything you said makes perfect sense. Eventually there will be either at least a guitar or bouzouki track up front, so that should provide some contrast. And the delay makes all kinds of sense. Thanks.

I would think distance would come from more lows roll off, not HF. Higher frequency carriers further, so things far away are like a high pass is on them. Also play with how you’re EQing the verb or delay, maybe cut mids from that.

I did that. I was at it for a long time. It just never quite got there.

I’m thinking of loud sound heard far away...football crowds, gunfire, freeway noise. It’s always the high end that carries for miles.

Unless your in the mountains, on a lake, with a piper standing on shore! Then it sounds like a whole army is coming for you😃

As far as math goes I know that higher frequencies are attenuated more by air. But I’m not sure it’s as simple as all that when we’re talking about actual sounds. High frequencies also reflect more, and sounds that are generated aren’t uniform with respect to frequency.

As a thought exercise... if a sound is “top heavy” in a way that outpaces the difference in LF vs HF attenuation eventually you’ll only hear the higher frequencies.

I agree that a low frequency foghorn will carry further than a higher pitched one. But I’m not sure that if you hear a marching band play from a mile away you’ll hear more low end than if you were in the stadium.

Turn it down.

Can’t believe no one has mentioned the obvious. Maybe that’s because it’s obvious?

Space layering will get you to where you want to be.

Honestly the answer is so simple people usually think there is some massive trick that is involved but it's really just a matter of using the real world and applying it to your goal via space/reverb plugins.

If you want something to be behind the scenes first of all (and you mentioned it) you need a sense of where the listener is standing/seated. Like in the movie "The Aviator" he wonders why the planes look like they're hardly moving and realizes it's because there is nothing behind them to give sense of motion, or in this case distance. You're going to use that analogy in reverse. The vocal, acoustics, electrics, piano basically anything that can seem to be close to a listener, you want to bring a dry representation of them to the listener. Balance and eq these so they blend together, but at least one needs to be a focal point for the up close reference. Also like mentioned above, volume. You don't want these dry components being to forceful or "loud" so make sure that compression is used enough to hold them still. Maybe let the vocal move more dynamically and keep these dry instruments synched down. Be careful with the bass, for what you're trying to do I'd pull out like the Pro-Q, HPF at around 40hz (24db slope) then place a node right about 300hz with a medium Q and pull maybe 3db-4db out. Now that you have the stage set, it's time to get the lush background of the "pipes" or whatever it is you're wanting to do this to.

Try to imagine first, the room in which the listener is seated in. Something like a medium room, not too much decay, but just some space or ambience, put this directly on the stereo track, not a send this is our "listening space". Now, create an aux track. Next imagine the area from the listening room to the point in which the "pipes" start. Imagine yourself at the bottom of that mountain, imagine all the surrounding structures, trees... anything like that and imagine what type of decay or reflection you'd from that point. Start with just a general Hall and start to manipulate the decay, pre delay and feedback until you feel like you're standing at the bottom of that mountain. Once you have that, make another aux track and direct the output of the "bottom of the mountain" aux track directly into it. Now, imagine what it could sound like if someone where yelling short bursts of words at you from up there (if you get a chance, check out Hofa's IQ Verb, it allows generic samples to be played into the verb you're creating.) Now I would go with something maybe like a Chamber or a Hall and roll the top end back to like 4k-6k. Start working the decay time, size and pre-delay (very important here, almost use it as a delay.)

Now this may sound like it would be this massive wash and you're never hear any discernible audio, but if you take your time, really imagine yourself in each of those locations and properly adjust the parameters of the Verbs, eq and compression, what you should get is a very distant sounding "pipes" behind all of that drier, brighter and compressed up close instruments. Also try panning the drier stuff hard left/right/center and the "pipes" pan the left and right of the final aux track as if you stretched your arms out at the speakers and created a triangle from your seat to each of the speakers. Probably in the neighborhood of <65 65>

I hope this helps and at least gets you thinking and closer to what is in your head.