When Slovenian tenor Ambroz Bajec-Lapajne was told to sing during his craniotomy, he blew his doctors away with a beautiful version of Franz Peter Schubert’s “Gute Nacht.” Undergoing open-brain surgery while awake at a Dutch clinic, Bajec-Lapajne sang so that doctors could monitor certain brain functions associated with vocal skills, and if they changed.

The surgery took place June 13, 2014 at the University Medical Center Utrecht, in order to remove a brain tumor from the singer who had been diagnosed with Glioblastoma multiforme (GMB). RT reports that GMB is not only the most common brain tumor, it is also the most aggressive, constituting half of functional tissue brain cancer cases. For those diagnosed, GMB is a virtual death sentence, killing 50 percent within the first year, and 90 percent in the first three years.

In order to make sure that Bajec-Lapajne would live a full life, sharing his passion with those around him, doctors opted for a craniotomy that kept the tenor fully conscious. During most craniotomies, part of the skull is removed to expose the brain, but patients can remain awake because they do not experience any pain. Even though the situation was awkward and discouraging at times, Bajec-Lapajne sang and continued to sing throughout the process.

At the beginning of the surgery we see surrounding doctors getting the opera singer ready to start one of his favorite tunes, while a surgeon is already working on his brain. When the accompaniment begins, Bajec-Lapajne starts his song, singing with the gusto of a man standing upright, in front of a large audience. Doctors are visibly awed, as he continues unperturbed. That is, until the surgery strikes a chord with Bajec-Lapajne, and his speech begins to slur before it fully fades out. Although this was set back, a doctor encourages him to start again, and Bajec-Lapajne is asked to sing the song in a minor key, in order to see if he could remember both the lyrics and vocalize the key change without an issue.

Several times throughout the video, the singer becomes stuck, forgetting lyrics, or stopping in the middle, only to start again softer and less assured. But he continues to fight it and always starts back up again, as doctors ensure that he is going to be OK.

This amazing sight is not the first video of its kind; in June, a man named Anthony Kulkamp Dias was asked to play the guitar for doctors as he had a tumor removed from his brain. His rendition of “Yesterday” by the Beatles also wowed doctors, while helping them measure his brain function.

Fortunately, a year later, Bajec-Lapajne is happy to say that the surgery was a success and he is doing well. He continues to sing professionally, and he still sounds amazing.