Sound proofing shelf frontage help

I was wondering if any of you had any advice for the front of a whole wall shelving unit I am planning on building (and the shelves as well if you have any suggestions). You see, although there is a cavity wall between this room and the next, I am wary of a noise complaint as it is a different flat’s bedroom. I will be using it as a music production room and ideally want decent acoustics as well as adding an extra these extra layers to stop leakage.
(I’ll draw some pictures and upload them to clarify what I’m saying)*
Two things I’ve been thinking about using:
1.  A high-density curtain hanging in front of the whole unit. While this could possibly deal with the main issue of a noise complaint better than the next idea, I’m worried it will create a bad mixing environment with a really ‘dead’ wall behind my speakers.

2. Hanging, sliding acoustic panels using egg box foam under a sheet of fabric. This will look like a normal acoustic panel with the fabric pinned around a timber frame. I was thinking of forgoing using any sheet wood so I could hang a piece of high-density carpet/ fabric at the back and not have the panel too heavy.
The wall measures about 3.2m W x 2.3m H so I was thinking of using three, maybe four hanging panels. It’s my understanding that a hanging panel would absorb more energy from the sound waves than one on wheels or in a sliding track.
To hang the panels the main idea I had was to use metal tubing (uncertain as to what material to use, conduit?). With the three panels, I would use two main lengths of it one on the same height, parallel to the other, with the distance between needed to stop the panels on either track hitting each other. From above or below it would look a bit like this U=====U (sorry if this doesn’t translate to your device well… See pictures) with the ends of the U going into holes drilled into the wood, extending as far as the shelves will be deep if needed. With four I would just have two sets of the same but smaller.
Sorry if this doesn’t make much sense, rushed off me feet at the moment.
Many thanks
Jay

*Sorry the pictures ended up pretty awful, just moving in, need a proper table…