Icaros, The Songs the Curanderos Use to Heal

On a forum I occasionally visit, someone asked a question about Icaros, the songs sung by curanderos, generally during ayahuasca sessions, but sometimes used without ayahuasca to heal, that seem to have healing power. The person then went further and asked why a given song--which are often just tones hummed or whistled--can cure illness when sung by a curandero, but are powerless when copied by someone else.
I put my two cents into the mix, and as I realize I've never discussed icaros here before, I'm putting my answer here as well.
Here's what I wrote:

At the risk of sounding like a know-it-all, and knowing that I know nothing, icaros rarely have words. They are vibrational songs, they are the ropes on which human spirits can glide out and be pulled back to earth. They are the sounds that allow a good curandero to know what every participant in an ayahuasca ceremony is knowing/seeing/feeling at every moment of the ceremony. They are also the tool the curandero uses to send people/souls to where he/she thinks they ought to be. He/She lifts one up, pulls one back, sits one in the corner,and sends one to another world, all with the same song. The songs come from the universal organ which runs this universe, seen and unseen, the sounds that make planets move, the sounds that create gravity, dimension. light.
To have someone copy those sounds will always be useless. It would be like a cover band doing a great guitarist's work--and that's probably too weak an analogy. Singing notes you've heard is generally meaningless. That's why most curanderos develop their own sounds, their own icaros. When they finally are treated to hearing the music that moves the universe, the sounds that make the machine move, they understand there are only two or three notes necessary. All the others are just pretty sounds.
And the same two or three or four notes that move the machine of the universe, on all its levels, are notes that realign bodies and spirit and so cure through that realignment.
So icaros copied have no value. Unless someone has heard that organ--or however your body/spirit quantifies it--the vibrations are just that. But once you know that sound, once that sound is your sound, once that sound is owned by a curandero, there is almost nothing on this measly plane of human existence he/she can't do with it.
The right vibration, the right tones are it. They can't be guessed. They are taught by spirits. Until someone has them they don't have them.
The songs with words are generally takeoff's on those genuine icaros, but I never met a curandero who thought they were particularly valuable except to center people under the influence who needed a bit of sound to get centered.
Of course, I'm just me and totally fallible, so I could be dead wrong on this.