Amplifying Anthems is an ability learned by the Mummers.
Music can have a profound effect on those who hear it. It can inspire courage, feats of extraordinary strength, sadness, and countless other emotions or effects. By tuning into the emotion and willpower projected via a variety of methods such as shouts or chants, a Mummer can inject a sort of "mental music" into the projection to accompany it, amplifying its effects.
Passively increases the effects of any group member's shout or chant, and passively increases the effects of the Mummer's own sigils and anthems.