Earworm Melody

You sing or play a catchy tune that only one creature of your choice within range can hear. Unless the creature makes a successful Wisdom saving throw, the verse becomes ingrained in its head. If the target is concentrating on a spell, it must make a constitution check with disadvantage against your spell save DC in order to maintain concentration. 

For the spell's duration, the target takes 2d4 psychic damage at the start of each of its turns as the melody plays over and over in its mind. The target repeats the saving throw at the end of each of its turns, ending the effect on a success. On a failed save, the target must also repeat the con check with disadvantage if it is concentrating on a spell.