I don't like Music as perception, that's much more the territory of MoSS and Social Arts. We chose RME over the Precognition themed CDP because it's not just about finding threats and secrets, it's also about academics and we had just decided the Hidden Moon to us should be about studying history and culture and learning from the past to grow stronger. So I could see RME's wisps to be Songseekers, representations of Ling Qi's curiosity that look for loot, songs and inspiration and share these things with their mistress. Like Sixiang shares their experiences with the Dreaming Moon, meaning they share all of our senses and not just sight. The wisps become something more than just moon eyes, drawn to expressive song and hidden secrets.
Inquisitive Study as it is now is capable of enhancing both sight and hearing, mostly concerned with discerning secrets whatever way possible, so we keep the base of it as is but with an addition to include "hearing" the Music of the world. Like we get a bonus to Perception whenever an active effect or technique gets triggered and can listen to the meaning of techniques around us as if they were a soulful composition. Which of course mean our wisps get that same ability. Add Erebeal's past sensing tech from two pages back and keep the scrying tech as is for now and we have an excellently thematic Art that's not Music so much as about Music.
The trouble with that interpretation of the wisps is that's far beyond us at the moment. We simply aren't capable of sustaining qi constructs over any relevant distance nor can we give them the independence necessary to search for stuff on our behalf. We will might get there eventually but just because a Great Spirit can do it doesn't mean we can. Indeed the Moon seems to do this a lot more than most Great Spirits, suggesting that even Great Spirits find it difficult. It also seems really awkward on a narrative level: we are curious about something, we send out a wisp to look into it, it investigates, it returns, we investigate, and only then do we get the information? Yrsillar could make it so that LQ just generally has the wisps running around and reporting interesting stuff but right now people telling us stuff like that is a big source of interaction with other characters and I'd be sad to see that go.
I'm also dubious of the idea of an Art having both past sensing and scrying, that just gives even more things to juggle and it seems like it would never actually be used.
Regarding Music perception, I get the sense that we are agreeing but then you say you don't like Music as perception, so I'm confused. It makes perfect sense to me that, just as a vision enhancing tech might not involve shining bright lights at what you look at, a Music perception tech might not involve actually playing any music.