You can't be charmed or frightened. In addition, as an action, you can imbue your words with a magical harmony or discord that affects all creatures of your choice within 30 feet of you. If a target can hear you, it must succeed on a Wisdom saving throw against a DC equal to 8 + your proficiency bonus + your Charisma modifier (a target can choose to fail) or be magically charmed (if you chose harmony) or frightened (if you chose discord) by you until you lose your concentration (as if you were casting a concentration spell).

Harmony. A creature charmed by the Voice of Harmony treats you as a trusted friend that is to be heeded and protected, carrying out any task that you ask of it in a polite manner, as long as the task does not conflict with its alignment. Any creature charmed in this way understands the meaning of your words, even if it normally can't speak or understand any language. Each time you or your allies do anything harmful to a target, it can repeat the saving throw, ending the effect on itself on a success.

Discord. A creature frightened by the Voice of Discord drops whatever it is holding and takes the Dash action to move away from you using the safest available route on each of its turns, unless there is nowhere to move. If the creature ends its turn in a location where it doesn’t have line of sight to you, the creature can repeat the saving throw, ending the effect on itself on a success.

If a target’s saving throw is successful, it is immune to your Voice of Harmony and Discord for the next 24 hours.