Thanks to a team of researchers at the Freiburger Institute for Musician’s Medicine, we get to watch this real-time MRI scan of baritone Michael Volle as he sings O Du, mein holder Abendstern (Oh thou, my fair evening star) from Tannhäuser. Via PLOS:

12 professional singer subjects of different voice classifications were analysed concerning the vocal tract profiles recorded with dynamic real-time MRI with 25fps in different pitch and loudness conditions. The subjects were asked to sing ascending scales on the vowel /a/ in three loudness conditions (comfortable = mf, very soft = pp, very loud = ff, respectively). Furthermore, fundamental frequency and sound pressure level were analysed from the simultaneously recorded optical audio signal after noise cancellation.

The data show articulatory differences with respect to changes of both pitch and loudness. Here, lip opening and pharynx width were increased. While the vertical larynx position was rising with pitch it was lower for greater loudness. Especially, the lip opening and pharynx width were more strongly correlated with the sound pressure level than with pitch.

Here are two more examples, including scales and Bruder Jakob/Frère Jacques:

Watch this video next: This is what your vocal cords look like.

h/t The Telegraph.