Originally inspired by the Kingdoms of Kalamar base class, and interest rekindled by this thread, I originally started working on it as a sorcerer bloodline. However, some abilities seemed too powerful for the "bloodline" concept, while others seemed too weak. So I spun it out into a base class framework to see how it fits.
The design philosophy behind it is to create a spellcaster that has a musical theme to its abilities, but not to pin down its role to that of a Siren. Rather, to allow it to be general with spells known.
I've got an idea for a capstone power, but I'm still refining it. I'm wondering if a capstone power is even needed given the other abilities.