Tauster's Whistling Fireballs

A three bright streaks erupt from your pointing fingers with high-pitched whistling sounds to three points you choose within range and then blossom into an explosion of flame. Each creature in a 10-foot-radius sphere centered on each point must make a Dexterity saving throw with advantage (because of the sound). A target takes 3d6 fire damage on a failed save, or half as much damage on a successful one.

It ignites flammable objects in the area that aren't being worn or carried.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d6 for each slot level above 3rd.