An MRI Shows How a Singer Sings Two Tones at Once (With the Music of Mozart and Brian Eno)

When peo­ple hear Anna-Maria Hefele sing, they won­der how she does it, and not just because of her impres­sive tra­di­tion­al chops. “While most of us strug­gle to voice one clear, dis­tinct note,” writes the Inde­pen­dent’s Christo­pher Hooton, the poly­phon­ic over­tone singer Hefele “can sing two at once, and move them around in sep­a­rate scales.” Also known as “throat singing,” this tech­nique “allows her to estab­lish a fun­da­men­tal note and then move the over­tone above it through dif­fer­ent notes, cre­at­ing an astound­ing, ethe­re­al effect.” With noth­ing more than what nature gave her, in oth­er words, Hefele man­ages to achieve a vocal effect more strik­ing than most any­thing heard as a result of even today’s most com­pli­cat­ed dig­i­tal process­es.

But what, exact­ly, is going on when she sings? These two videos, record­ed with Hefele per­form­ing inside a mag­net­ic res­o­nance imag­ing machine at the Insti­tute for Musi­cian’s Med­i­cine at the Uni­ver­si­ty Med­ical Cen­ter Freiburg, shed light on the mechan­ics of poly­phon­ic over­done singing. “What you see in this dynam­ic MRI-record­ing is the tongue move­ment in the vocal tract while doing over­tone singing and nor­mal singing,” says the descrip­tion.

“The posi­tions of the tongue forms the res­o­nance cav­i­ties which delete all not-want­ed over­tones in the sound of the voice at a cer­tain point in time, and then ampli­fy a sin­gle over­tone that is left, which can be heard as a sep­a­rate note above the fun­da­men­tal.” It has, in oth­er words, as much to do with sup­press­ing all the tones you don’t want to sing as with empha­siz­ing the ones you do. Hard­ly the eas­i­est musi­cal trick to pull off, much less inside an envi­ron­ment as unfor­giv­ing­ly noisy as an MRI machine.

But you can still learn the basic tech­niques, and from Hefele her­self at that: pre­vi­ous­ly here on Open Cul­ture we’ve fea­tured Hefele’s own demon­stra­tion of and how-to lessons on over­tone singing. No mat­ter how well we our­selves learn to sing two notes at once, though, we’d nev­er­the­less have lit­tle idea what’s going on to let us make such sounds with­out these reveal­ing MRI videos. (Oth­ers have sim­i­lar­ly exposed the inner work­ings of beat­box­ing and opera singing.) The footage also under­scores the respectable musi­cal taste of Hefele her­self or her col­lab­o­ra­tors in this research project, select­ing as they have the musi­cal exam­ples of “Sehn­sucht nach dem Früh­linge” by Hefele’s coun­try­man Wolf­gang Amadeus Mozart and “By This Riv­er” from singing advo­cate Bri­an Eno’s clas­sic LP Before and After Sci­ence — though you might call this an exam­ple of music made dur­ing sci­ence.

Relat­ed Con­tent:

Musi­cian Shows How to Sing Two Notes at Once in Mes­mer­iz­ing Video

How to Sing Two Notes At Once (aka Poly­phon­ic Over­tone Singing): Lessons from Singer Anna-Maria Hefele

Sci­en­tif­ic Study Reveals What Made Fred­die Mercury’s Voice One of a Kind; Hear It in All of Its A Cap­pel­la Splen­dor

The Hu, a New Break­through Band from Mon­go­lia, Plays Heavy Met­al with Tra­di­tion­al Folk Instru­ments and Throat Singing

What Beat­box­ing and Opera Singing Look Like Inside an MRI Machine

Bri­an Eno Lists the Ben­e­fits of Singing: A Long Life, Increased Intel­li­gence, and a Sound Civ­i­liza­tion

Based in Seoul, Col­in Mar­shall writes and broad­casts on cities, lan­guage, and cul­ture. His projects include the book The State­less City: a Walk through 21st-Cen­tu­ry Los Ange­les and the video series The City in Cin­e­ma. Fol­low him on Twit­ter at @colinmarshall or Face­book.