Cillian's Acoustically Sloshed

Choose a creature within 30 feet of you. They must make a Constitution saving throw. On a failed save, your musical performance rattles their synapses. Choose a damage type or Strength/Dex based melee attacks. The creature's damage of the chosen type is halved for a number of rounds equal to your Charisma modifier or until you lose or drop concentration. The affected creature can repeat the Constitution saving throw as an action, attempting to break out of the magically induced stupor.