Well, I suppose I should also put my two cents in.
The goal here is to win the challenge, and thus we need to understand what the challenge is. Here is what we know of the challenge:
Later that day, she found a neatly printed page slipped under her door when she emerged from the meditation room to quench her thirst. The challenge had been decided. It would be a contest of composition. They would each compose a new piece over the next three days, and then present it to the Elder overseeing the challenge. After presenting in turn, they would then vie directly against one another, to see whose message was the stronger.
So, the question then becomes which message is stronger. That could mean a lot of things, but given that music is about expressing oneself, it is probably a combination of the strength of our message as well as our ability to communicate it.
Zeqing probably has the strongest insight to give, but it is incredibly inflexible. Also, I feel that we would be using her insight for this piece would be communicating something that we don't personally have, and thus the message created from the insight would be diluted. So while I feel that this is a powerful message, I also feel that our ability to communicate the message won't be top notch and thus not the best use of our time. (Additionally, using our super powerful teacher's insight to craft a message we want to give for our challenge just seems... weird for me. Let's craft our own message.)
Sixiang is closer to our level and is also heavily aligned with music and creativity. Being a muse and inspiration, as well as our bound spirit and thus more understanding of our quirks and nature, is just an additional benefit. However, Sixiang is distracted by something, and thus the help that they might give could be limited as it may take some time to push her out of whatever she is doing right now. They probably have some good insights to give on composition work and have a more diverse message that they could convey. Additionally, I feel that this might be a good opportunity to compose and express what we felt during the Bloody Moon dream, and Sixiang would be perfect for that.
Friends and family would probably be the most helpful in being able to hone our message and strengthen our ability to express it. If people who are not musically inclined are able to feel and understand the meaning of the message through our song, then it is likely that those who are will be able to understand and appreciate it even better. The insight that they could give, however, in composing such a piece would be limited though. So I feel that this choice would be purely for strengthening our ability to express our message, and not very helpful when it comes to composing the said message.
With all of that, I believe I am going to choose
[X] Sixiang was her muse and her friend. Ling Qi was tired of being ignored. She would get Sixiang's attention and help.
I feel that this is probably the most balanced option between composing a strong message while also getting help in being able to express it. Also, I do want to get Sixiang out of her funk and this is probably the best way to do that. While it may take a bit longer than a day to get her attention, I'm sure that in the time that we'll have to both be working on this we can create something spectacular. Also, I feel that this is the best opportunity to compose the feelings we experienced during the Bloody Moon dream into song, and start working on resolving the issues we are having with it. Although... it is probably too private for Ling Qi to actually publically express in a competition format. So, we'll see.