Ceiling construction question

Hi all - sorry if this is a stupid question - I've read through the USG manual and the SAE site, and I'm not sure I've come across the answer yet. I'm building a basement studio where the primary sound concern is isolation from the floor above. I'm under the impression that this means I want to ceiling to overlap the walls, right? (And this would mean constructing walls that come to about 1/4'' under the ceiling, topping them with neoprene/acoustic caulk, right?) Let me know if I'm confused about any of this. So my question is - I'm dealing with a space with load bearing wall framing that already goes up to and is attached to the joists in the ceiling. How much isolation do I lose by having the walls, rather than the ceiling, overlap? (I'll be caulking everything with acoustic caulk). Is it a probem for sound transmission that the framing for the walls is already attached to the joists of the ceiling? I also have to build one new wall - should I attempt to build the ceiling over it first, or will this not matter so much if the other walls are already in place as mentioned above? Thanks!

This is probably the best way of doing this - however, if you're not planning on using Resilient Channel, we need to discuss flanking noise... Steve