Taron's Spectral Blades

As the caster strums the strings of a stringed instrument a blast comes forth and 8 spectral blades appear and race forward.  Each creature in a 100' line needs to make a Dexterity saving throw.  A creature takes 8d6 slashing damage on a failed save, or half as much on a successful one.  

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.