Sam Johnson turns vocal acoustics into practical studio tools — formants, turnover and decoupling — then proves it live on two teenage singers.

Sam Johnson takes the part of vocal acoustics most teachers nod along to and never use, and shows you how to actually teach it. You'll work through harmonics, first and second formants, and why long tubes lower formant values and short tubes raise them — then translate that into the relationships you hear every day: hooty timbre (F1/H1), the chest-voice yell (F1/H2), and the decoupling that lets a singer flow between them. He shares his exact toolkit: the turnover experiment, octave slides on "oo," descending major scales, exaggerated "trains crossing," nasty short-tube sounds, the yawn/tongue-release system, and two ways of opening the jaw. Live work with two of Marianne's high-school students closes it out.