Paul von Jankó
He first studied mathematics and music in Vienna, where he was a pupil of H. Schmitt, J. Krenn and Anton Bruckner. He then moved to Berlin where he during the years 1881 and 1882 studied mathematics at the city's University, and piano with H. Erlich. In 1882 Jankó invented the Janko keyboard, a 6-plus-6-keyboard with 6 rows of keys.