Uniting Rhythm

You play a song brimming with hope and magic. Ally creatures are united by your steady rhythm and gain focus in battle. Choose a time signature from the table bellow. When a willing ally creature's attack roll is a multiple of the time signature (top number), they gain benefits from the table bellow.

if all affected creatures attack's hit and benefit from the spell, the duration is increased by 1 round per spell slot level up to a maximum of 10 rounds.