In the curanderismo traditions I study music is the main mode of magic and healing. If you want to cleanse the patient you sing. If you want to cleanse the room you sing. If you want to call on spirits, center your visions, navigate your visions ect, you sing. Basically everything can be done with singing.
I incorporate a couple different styles into my personal practice, but mostly I sing in Quechua and Shipibo. I didnt know either language when I first started singing - the songs would just come to me from the spirits and eventually I learned what more of the words meant.
Here is an example of a Shipibo icaro (icaro = medicine song):
Here is a recording of a female shaman I stayed with singing in Quechua and Spanish. This song calls on the transformative power of the butterfly (mariposa = butterfly):
Here is a more modern style icaro. This one is in Quechua and has guitar (I sometimes play this icaro on guitar - it calls on many plant spirits to help the ceremony):
Sometimes the icaros have a basic structure that is followed, but most often they are improvised on the fly and each time they are unique. Most likely when you hear an icaro that song will not be sung that way ever again - it was sung that way in that moment for a specific reason.
Here is an example of how an icaro might start.... This is a Shipibo phrase with an english translation.
rama cano abanon
nocon pae canabo
jacon mabo canobo
enque sua ayonquin
sua sua vainquin
punte punte vainquin
now i open the vision
the visions in my mareacion
their dark energy
the dark bad air
i do clean
cleaning is going on going on
straightening is going on going on
In this example they basically just say what they are doing. This one calls forth the bad visions they are having and then cleans them (this is usually how they clean - call the energy up and then send it away). So if you start to understand some of the words then you can easily write your own songs and improvise them in the moment more easily - after a while it becomes more habitual and easy and your intuition can guide most of the process. The more you can get out of the way and let the song flow through you the greater the songs effect in most cases....
Hopefully this gives you a little more understanding about how icaros work and maybe even a few clues on how to start learning them yourself!