Codwell's Calamitous Composition

Flourishing the conductor's baton used in the spell's casting; you conjure a cube of spectral sheet music 40ft on each side centered on a point you see within range. Symphonic sounds emanate from the area for the duration, audible up to a distance of 300ft. The spell's suppressed if at least half of its area is inside an area of Silence or similar sound-blocking magic.

When you cast the spell, choose one of the effects below. As an action on subsequent turns for the duration, you can choose an effect again. You can't choose the same effect twice in a row. If you end your turn without having used an action to choose an effect, make a DC 15 Constitution save. On a failure, the spell ends.

Fanfare. Once per spell only. Creatures of your choice inside the spell's area or within 20ft if it can hear you gain 20 temporary hit points, lasting until the spell ends. Also, creatures of your choice inside the spell's area or within 20ft of it that can hear it must make a Wisdom save. On a failure, a creature's charmed by you until the start of its next turn. While charmed, the creature uses all its available movement on its next turn (before taking any actions) to move as far into the spell's area as possible. It avoided obvious dangers, such as fire, but will trigger opportunity attacks to move towards the spell.

Booming Brass. All creatures inside the area must make a Constitution save. A creature takes 6d10 thunder damage on a failure or half as much on a success. A creature that fails is also Deafened until the start of your next turn.

Pounding Percussion. Until the start of your next turn, standing from prone in the spell's area costs 2x as much movement. Also, creatures of your choice in the area are inspired by the rhythmic beating of drums. Until your next turn, these creatures add 1d4 to their weapon attacks and 1d4 thunder damage to their weapon attack damage rolls while they remain inside the area. A deafened creature gains no benefit from this effect.

Shrieking Strings. Creatures of your choice in the area make Wisdom saves. On a failure, a creature takes 3d10 psychic damage and is Frightened of you until the start of your next turn. While frightened this way, a creature's speed is 0 and has disadvantage on Wisdom saves. On a success, a creature takes half damage and no other effect.

Wailing Woodwinds. Until the start of your next turn, the spell's area is difficult terrain. Also, creatures of your choice in the area make a Strength save. On a failure, a creature's pushed up to 30ft in your choice. You can choose a direction for each affected creature. You can push a creature half as far to knock it prone.

Finale. Once per spell only. You can use this effect if you have used each other effect from the spell at least once during this casting. All creatures of your choice in the area make a Constitution save. On a failure, a creature's stunned until the start of your next turn. You can choose different creatures in the area to instead benefit from this effect: chosen creatures regain 30 hit points, any frightened condition on them ends, and until the end of their next turn, they crit on attacks of 18, 19 or 20.

At Higher Levels. When you cast this spell using a slot of 8th or higher, you can use 2 different effects instead of 1 when you initially cast the spell. This increases to 3 different effects using a 9th-level slot.