The Anthem
The Root of Arcana
The Anthem, sometimes called the Arcane Anthem, is the force by which magic permeates Draconem. It is magic and energy and song, pure and powerful, in the form of a great symphony that sings and hums, always, in all things.
While the symphony of the Anthem grants access to common arcana, there is one section of the orchestra barred from the common mortal. The Gods, said to have written the symphony of the Anthem, have cordoned off the mending-song. These arcana are divine, often healing, and are restricted only to champions of the Gods.
While the source of the Anthem is unknown, it is known to be infinite.
Singing With The Anthem
Mortals fill their lungs with the anthem and let it course through them into other parts of their body, able to harness common arcana: mould elements, cut through the astral fabric and travel the threads into other realms.
To use the Anthem is to expose your being to it - if souls do exist, then harnessing arcana is exposing your soul to the harmonies of the cosmos. Whenever casting, one must hold their breath in order to maintain it, or 'hold the note' as it is colloquially referred to. Of course, holding a note too long can result in fainting, damage to the brain or even death. The ability to cast is directly tied to one's ability to hold their breath, and to sing with the anthem (otherwise known as casting arcana) means one must have lungs - constructs are therefore unable to use arcana in this way. One's entire body vibrates with the Anthem when casting with it, humming through your chest, zipping through your fingers.
It is a feat to learn to sing with the Anthem quietly, but not unheard of.
Classifications
Every person have a 'classification' of instrument associated with them. This Classification is often random and final - designated at birth and unchangable. These Classifications include string, wind, percussion and electric. There are further subdivisions (the bassy lower registry of strings, all double-bass and hurdy gurdy - or tinny percussion, all cymbal and high-hat). Consider this as you make your caster, even if they are not a spellcaster - for everything sings, in its own way.
Octaves, Spell Levels, and 'Holding the Note'
There are ten octaves that human ears can hear, and thankfully, when singing with the Anthem, your own vocal registry is not relevant to the octaves in which you sing, for it will sing with you.
First Octave is the easiest to sing at, the low, droning hum of the Anthem is often the first harmony that novices hear, as it is always present. This is mechanically a cantrip.
After that, Second Octave all the way through Tenth Octave represent 1st through 9th level spells. Often, a 9th level spell, or a Tenth Octave spell, is the climax - the final blow, built up to and culminated.
Deafness and Arcana
Theoretically there are Octaves above Ten and below One, though those are the only ones the human ear can pick up on. Deaf mages are taught in magical systems created by hearing scholars, so they themsleves don't hear the Anthem in the same way that the systems and mentors that teach them do. Those without hearing still 'hear' the Anthem, though it is by very different means - every change, every note, the different Classifications and subdivisions of a caster, all of it can be noted, even without hearing.
If there ever were to come a person who could learn to harness Octaves above or below, the chances are, they would be d/Deaf.
