Attaching wall to ceiling or not

[shenes]

Hi all,

First post from swedish mixer/producer here. I've been reading the forum for years and have found all the info here to be of great help and now i have a specific question that i can't find an answer to.

I am planning a complete rebuild of my basement studio/rehearsal space. The reasons for the rebuild are many but the first/main concern is isolation from neighbours/outside.

The studio is located in a basement under a courtyard, no neighbours directly above, thick concrete slab and dirt below. The studio ceiling is steel stud reinforced concrete. We can hear people walking on the roof above and muffled music (loud drums) can be heard when up on the courtyard. We also believe the concrete ceiling creates a flanking path that can reach apartments next to the courtyard. No major neighbour issues but we know they can hear us and we'd rather not completely rely on the their good will towards us in this matter.

(The basement walls are 3ft thick massive concrete so i'm not so worried there). The plan for the ceiling is wodden studs straddeling across the width of the room (4meters) with 2 layers of green glued sheet rock. Pink fluff between studs above the sheet rock.

We are also building dividing walls between storage, live room and CR. Isolation between those rooms are not AS critical but we are aiming for STC45-50. (with separate ceiling constructions in every room, hanging down between walls.)

Should i attach the wall frame to the ceiling or should i leave the outler leaf floating and thus avoid flanking noise from the new wall?

If the answer is NO, leave the ceiling floating: should make a soft seal between ceiling and wall?

Best regards,
Johannes