About source materials....

[IfritSlasher]

If a book references another book, like say how Flamesinger references Ultimate Magic's Fire Music feat, are you required to have the book being referenced for the archetype to be legal?

[Gyre Glenross]

IfritSlasher wrote:

If a book references another book, like say how Flamesinger references Ultimate Magic's Fire Music feat, are you required to have the book being referenced for the archetype to be legal?

I would say that to be a Flamesinger requires the book Flamesinger is in. If you want your Flamesinger to use the Fire Music feat, then you would need Ulitmate Magic as well.

[Starglim]

You need the published source for any rules that the GM might need to check. If Flamesinger gives you Fire Music and doesn't contain complete rules for it, you'd need sources for both.