About Sorcery on Erde
There are two kinds of sorcery here on Erde. One is Clearsong; the other is Darksong.
Clearsong is what a sorceress uses to deal with things that are not alive and have never been alive. Stones, metal, bricks, if there's not too much straw in them, glass…
Darksong is used for living things or things that were once alive — like wood or bone. Darksong also takes more skill in singing the spells, and more energy. If you do too much of it, a Darksong spell can kill you. So can a Clearsong spell, but it takes a much bigger spell.
What is a spell? It is the combination of music, sung words that match the music, and the meaning of the words themselves. They all have to match. You can speak the words to a spell to music, and nothing will happen. You can sing the words of a spell — and unless you are very, very good, nothing will happen. And if it does, without music, it will take most of your energy — and if you survive it, at least until you're experienced as I am, you'll feel like someone's lancers ran their mount over you.
There are rules for sorcery. First, no sorceress, or sorcerer, can cast spells that directly affect her. I can't change my appearance or make myself older or younger, or less tired, or heal my own wounds. Second, the stronger and better the supporting players, the more effective the spell. Third, sorcery does not create things from thin air. It rearranges what is already in this world. Finally, sorcery is limited by the strength and talent of the sorcerer and sorceress.
Magic, like everything else in this world, takes a lot of skill, a lot of raw talent, a lot of training, and you can only do so much.