I mean that if there were a mezzo-soprano, but also a soprano available to review a piece that I would define as very simple, I would send it to them,
as I wrote, it is a piece for piano and voice.
Then, based on the level of difficulty encountered (which in my opinion, if it isn't modest, is almost non-existent), and on whether or not they are available to perform it, an agreement could be reached for a possible recording.
The other thing I meant to say, which I encounter a bit too often, is the lack of consideration for such a "collaboration," both because it is not a well-known piece, perhaps written by an established composer,
and because we are not talking about large earnings; I am sorry to say it, but this is also one of the reasons for the "avoiding it a priori."
Personally, I am not someone who gives compliments or flatters someone to get something, and at the same time, I understand that it is one thing to perform pieces of a certain level, in a location of a certain prestige, and even to be paid considerably; it is another thing to "settle" for singing unpublished pieces every now and then.
All understandable, but only up to a certain point.
Who knows, maybe if I had said "I offer 300/400 euros," someone would have worked their tail off; the problem is that I literally have to work my tail off myself to reach that figure.
This argument also applies to others who perhaps do not have the courage to say it, because that way one makes a "not splendid impression," but diplomacy, even if understandable,
must not mask a person's true character; one must say what they think, within limits, but one must do it.