I'm making a Bjornaer character with a wolf as a heartbeast, and I had an idea I would like to throw onto the forums here for some comments. If I get the virtue Performance Magic for this character, could wolf howling be counted as a performance? So in effect, when in wolf form, this Magus casts his spells through his howls.
What do you guys think? 
E.
Sure, why not? Sounds good to me.
Which make me think that House Bjornaer would probably know an initiation script for this virtue. And for Subtle-Casting too. Just too darn useful for Bjornaer not to develop the scripts. Hmph.
My first thought is: bending the rules backwards.
But then again, I don't know how serious performance magic normally is, what it costs you and exactly how strong the heartbeast is.
But as said: I think a wolf as heartbeast is already quite strong, add magic wielding to that and you have to be sure everyone in your troupe likes powerplaying. (since there is nothing inherently wrong with strong characters, as long as the rest of the troupe likes it too)
I don't think it's overly power-gaming. Instead of taking two Quiet Magic (2 points) he's taking Performance Magic (1 point) to cast spells at wolf form without penalty, but at the cost of having to make sounds to cast spells instead of doing so quietly. Sounds reasonable to me.
Especially as he can't howl while in human form 
He might if you step on his toe
Remember that is also the virtue Unbound Tounge, which allows a Bjornaer to speak while in heartbeast.
The way I'd suggest using Performance Magic for a Bjornaer is thus:
-It's called Howling Magic
-It's a verbal action which can reach long distances in the right conditions, and gets the Duration: Performance
-It's also a physical action, because of the posture needed, and the wolf must stand or sit still while howling.
-He can only do this in heartbeast form, unless he is initiated into Thieramorphy (that allows the Magus to change partially).
-Also, the ability used is Heartbeast, no Music or some other ability. This ability has to do with the knowledge of being the wolf (or other animal).
-If disturbed in some way, use Heartbeast ability instead of Concentration to keep the spell duration going.
That's my suggestion. So this would almost be it's own Minor Mystery Virtue.
E.
By the rules as written, I'd say "no" - quickly followed by "but screw that!" It's a great idea, and perfectly in keeping with the spirit of the game and, perhaps more importantly, the character. Not every Virtue and Flaw can be included in the rules, and this is a creative interpretation that has drawbacks (making a LOT of noise!) that balance what might otherwise seem like a munch move (avoid the need for silent casting).
I like it. 