You've learned to transform effects using music.
While you are playing your instrument you may use these effects

The Harmony
As an action, you may share any single target effects received by you with any creature of your choice within 10ft.
Effected creatures keep this shared buff effect until the end of their next turn.
At level 9 it becomes a 20ft radius and at level 17 it becomes a 30ft radius

The Remix
Cantrips cast through your instrument deal Thunder damage instead of their regular damage type

The Vibes
As a bonus action, you surround yourself with a musical aura which emanates 5ft from you in every direction.  It lasts until you're incapacitated or you dismiss it as a bonus action. 
Each creature of your choosing that enters or ends its turn in the area takes Thunder damage equal to your Charisma modifier (minimum of 1 damage).