Search a dict

Hi, I have probably a pretty amateurish question about [dict] and JS.

I'm testing using [dict] to store information about samples in buffers. The structure of the [dict] as I imagine it looks something like:

{
    "sound1" :     {
        "descriptors" :         {
            "pitchclass" : [ 0, 1, 3 ],
            "noisiness" : 0.3,
            "loudness" : 0.8
        }
,
        "playback" :         {
            "buffer name" : "vla_trem2s",
            "sample start" : 66551.929688000003807,
            "sample end" : 71836.484375,
            "main out level" : 0.01,
            "aux send level" : 1.2714,
            "pan setting" : "all"
        }
    }
,
    "sound2" :     {
        "descriptors" :         {
            "pitchclass" : [ 0, 4, 8 ],
            "noisiness" : 0.9,
            "loudness" : 0.1
        }
,
        "playback" :         {
            "buffer name" : "vla_temp",
            "sample start" : 1000,
            "sample end" : 9999,
            "main out level" : 0.5,
            "aux send level" : 0.1,
            "pan setting" : "left"
        }
    }
}

(sorry if the formatting is wacky, I can repost as a maxpat if that's a problem)

Now, let's say I want to find all sounds that have pitch class 0. What I want returned is "sound1" and "sound2." Or, just sounds with pitch class 4, which returns only "sound2."

Follow up feature: Rank all sounds by loudness, low to high, which I want returned as "sound2" followed by "sound1."

I've sort of built a primitive version of this using [coll] but I'm reaching the limits of organization and usability. In my [coll] version, I'm iterating through my data at each request, keeping track of the data index. I had a hunch that [dict] in combination with some JS might be a more descriptive, expandable, and readable route to try. However, my JS and [dict] skills are coming up short.

Any help is greatly appreciated!