How Songs Are Created on Instagram: "In 2014, German singer Anna-Maria Hefele stunned the world with a viral video showcasing polyphonic overtone singing, a vocal technique that lets her sing two notes at once. By skillfully shaping her mouth, tongue, and throat, she amplifies harmonics above a base pitch, producing clear, flute-like tones. Trained at the Mozarteum University in Salzburg, Hefele has since performed worldwide, blending art, science, and education. Her unique voice has been studie