Kaelin plays real singers — flipping, splatting, damaged, barely mixing — and works a room of teachers through what is wrong and where they would start.

This is ear training, not lecture. You'll listen alongside a room of certified teachers as Kaelin plays anonymous recordings — a breathy choral soprano letting go at E4, a 16-year-old boy dragging chest through his first bridge, an audibly damaged professional voice, a 23-year-old belting a high note on a raised larynx — and every time you get the same two questions: is that a mix, and where would you start? You'll pick up his "rooms" model of the registers, weigh straws, squeaks, lip trills and vowel choices against each other, and hear why he defines mix by airflow, resistance and vowel instead of chest and head.