Henricus Grammateus

https://en.wikipedia.org/wiki/Henricus_Grammateus

Henricus Grammateus (also known as Henricus Scriptor, Heinrich Schreyber or Heinrich Schreiber; 1495 – 1525 or 1526) was a German mathematician. He was born in Erfurt. In 1507 he started to study at the University of Vienna, where he subsequently taught. Christoph Rudolff was one of his students. From 1514 to 1517 he studied in Cracow and then returned to Vienna. But when the plague affected Vienna Schreiber left the city and went to Nuremberg.

In 1518 he published details of a new musical temperament, which is now named after him, for the harpsichord. It was a precursor of the equal temperament.

In 1525 Schreiber was back in Vienna, where he is listed as "Examinator", i.e. eligible to work holding exams.