Sheesh, everybody's a smart-ass...

No more containers, PLEASE! I'm cryin' "UNCLE!"
Sorry 'bout that! I couldn't help it: I just couldn't
contain myself there....

OOOPS! OK, I'll shut up now....
Maybe ONE exterior entry airlock, that opens into the main space, with doors large enough to get a piano through, without dismantling it...
One suggestion: Don't try to do "double doors" in each leaf in order to get a really wide door. In other words, don't do two doors hinged on opposite sides that meet in the middle. Those are really hard to seal acoustically. Instead, think of a single large door in each leaf. Maybe make it a sliding door, if it would be too big to hang on hinges. But however you do it, make it massive, heavy, and well sealed. "Mass" and "airtight" are two of your new best friends!
(The Boston guys would hate it, I airbrushed "flames" onto it...)
Sacrilege! You better hope they never find out!
They're evidently surplus light panels from a library build. Triple paned glass, argon filled, on mech risers, thermostat operated. ... Each unit sits on a motorized riser that lifts the skylight up, ... The skylight channels are concrete boxes, cast in place (inner and outer walls with insulation inside them). They're cast right into the roof surface. ... He did a good albeit neurotic job. ...
I'd say "neurotic" is putting it politely! The more you talk, the more this sounds like an "end-of-the-world" type survival bunker, designed to survive pretty much anything short of a direct nuclear strike!
From what you say, I think Brien ("xSpace") has the right idea: Acoustic absorption panels on the shaft walls, to damp resonance in there, and then maybe thick laminate glass directly underneath each shaft, built into your inner-leaf ceiling, to keep the light. Since those skylights would then be part of your outer leaf, you'd have to close them permanently, remove the opening mechanism (or at least, disconnect the power), and seal them all around, airtight. You'll have something like a five-leaf system in there(!

!), so low frequency isolation will be out the window (excuse the pun!) but I don't see there is much else you can do about that, short of ripping them out or sealing them up completely. I'm thinking that there is so much mass in there with triple-paned argon filled laminate glass panel, and a five foot air gap, plus another really thick laminate glass pane in the inner-leaf ceiling, that you probably should be OK despite the multi-leaf system. I suspect that your resonant frequency in that system will be low enough that it won't be an issue. But I'll leave that up to the experts to figure it out for certain.
I got ya. And whaaaaa? More calculations? My head hurts already!
Ohhhh, you haven't even STARTED yet with the calculations yet! Your materials shopping list should include a truck load of Aspirin, as the first priority...
Seriously, don't sweat the calculations too much: most of them are easy, simple math, and for the really complex ones there are web sites and spread sheets where you can just plug in the numbers, and it will draw pretty graphs and curves and tables for you to state at.
Okay, "inside/out" is labor intensive, but it's a labor of love,right? Can it be achieved by a DIY'r? Or do I have to start looking for a buyer of my other Harley?
You have ANOTHER one of those monsters? WOW!!!! You sure are a sucker for punishment, aren't you! ???
Seriously, inside-out is not all that hard to do. Its just harder than a normal "right way out" wall. It certain is DIY territory, but you might need an extra few pairs of hands at critical stages, such as lifting a wall that weighs a few hundred kilograms from horizontal to vertical, and setting it in place... So you shouldn't need to sell the other Harley to do it! In fact, maybe you can use the Harley to help lift the walls unto place. It sure has enough power to do that!
Inside-out requires careful planning, since you don't have access to the drywall side of the wall once it is up, so if you forgot to do something, like seal or tape or mud or whatever, then the only option is to lie the wall down again and fix it. You also have to consider your construction sequence carefully, to make sure that you will have access to all the places you need to get to at each stage. So that you don't "paint yourself into a corner", so to speak, such as needing to get to some place to caulk it, nail it, bolt it, frame it, clean it, or whatever, and then finding out that the place you need to get to is on the other side of your inside-out wall. That's where I am right now: planning my construction sequence, and modifying my design every now and then, so that it actually is possible to build it. I'm having trouble figuring out the ceiling construction sequence at present, since I'm also doing an inside-out ceiling, but the plan is coming together slowly.
In other words, you need to plan it very carefully, and think it through, before you ever buy a single stud or nail.
I'd give ya a lot more for the info you've shared, so far. At least a buck!
Ahhh, The last of the big spenders!

Thanks for the compliment, but please don't ever trust my advice too much, as I'm not an expert! I've just been intensely studying and researching and reading and learning about this whole acoustics and studio build thing for a while, but I'm nowhere near up to speed on it yet. I can maybe waffle on about the basics for a bit (I'm good at waffling, like Ro said! Maybe you noticed?), but when the tough questions come up, I'm not the guy to talk to about that. Listen to the real experts around here, especially if they tell you to not to do something that I suggested!
I'd have to build dampening panels about 5' x 5' x (adjusted + or - for whatever thickness) and then just hoist them into place, so they could be attached to the walls inside the skylight. Plus, it'd look really cool...
That should work. My guess would be maybe four inches thick should do it. Stuff them full of 703, rockwool, fiberglass, or some such, and put an acoustic cloth cover. Illuminate to taste. (Neon, strobe, laser, LED, whatever.)
It's like a foamed coffin in there. I suspect that you're right, and my prob will be adding "live surfaces" to brighten things up.
I'm thinking that you'll probably be best leaving your floor as plain concrete, if it is in good shape, or maybe glue laminate flooring on top. A live floor is a good thing.
Have you done any acoustic tests in there yet? It might be an idea to do a basic analysis before you get too far ahead, just to see where there might be potential issues.
- Stuart -