Requirement: Perform 17 ranks
Base effect: All allies within 30 feet gain a +1 morale bonus to AC, CMB, and all saving throws. The bonus becomes 1 point higher at 5th level and every 5 level thereafter (to a maximum of +5 at 20th level).
You channel a spark of immortality in your allies, making them more resistant until the end of your next turn.
Weak Refrain: allies within 30 feet gain DR 3/–.
Intermediate Refrain: allies within 30 feet gain DR 5/– and SR 20.
Strong refrain: allies within 30 feet gain DR 10/– and SR equal to 7 + your siren level.