This was quite a challenge. I found a nice (and free!) photogrammetry model at Sketchfab of the Charterhouse in London:
https://sketchfab.com/3d-models/the-charterhouse-great-chamber-50e692c037784347b289d7bbcb318bedI loved it and thought how I could I make this a part of a scene in TG. I cut the model apart so that I had the ceiling, the chandeliers, the walls and the floor as separate parts, and additionally cut out the window parts, made them more self illuminating and added more light planes in the shape of the window areas to enlighten the stuff that I wanted to add to the scene.
I replaced the ceiling, the chandeliers and the floor with my own ones to give them a surface that was interacting with my models.
Then came the fun part. I remember long time ago I saw a documentation about the rehearsals of Sting's first solo tour after The Police split up. They rented a beautiful room in a chateau in France (as far as I remember), and I thought, wow, this is very inspirational. So I had the idea of creating a similar scene with loads of my favourite instruments. Unfortunately I can't play any of them, but nevertheless I love them all.
It took quite some time to find all the models, but eventually I was successful. Most of the objects are free ones. I purchased the wooden table in the foreground, the guitar effects pedal board (barely visible) and the Mellotron M 400. All of the models were under 5 Euros. I used 3D Coat to make the Mellotron look rather used and old. The Hammond B 3 and the Leslie are made by myself years ago, and I had used them before for some scenes.
The drummer is a free character from the web, which I reposed in Mixamo, and I replaced his head by the one of a free laser scan guy with a nice smile.
The drum set was a simple one with one bass drum and two toms, but I decided to make it a bit heavier by duplicating the bass drum and some crash cymbals.
I know, there's a serious lack of cables. Actually there's not even one. I had no idea how to create cables for all devices, so I guess everything is radio controlled...

The DOF of the vocal microphone in the foreground is postwork. The rendering in 3K took about 15 hours (mostly because of the curtain!), and I didn't want to render the whole thing again.