This was also pretty cool. Try to make length logarithmic

src/App.vue

@@ -457,7 +457,8 @@ export default {
           let bandSum = 0
           for (let j = start; j < end; j += 1) bandSum += freq[j]
           const avg = bandSum / Math.max(1, end - start) / 255
-          const shaped = Math.pow(Math.min(1, avg * 1.4), 1.6)
+          const amplified = Math.min(1, avg * 1.2)
+          const shaped = 1 - Math.pow(1 - amplified, 2.5)
           this.tentacleLevels[i] =
             this.tentacleLevels[i] * 0.6 + shaped * 0.4
         }