Born in Lippstadt, as an eight-year-old, Hansen had his first piano lessons in his hometown, and only two years later he was giving public concerts.
Further concerts followed under Eugen Jochum, Willem Mengelberg, Herbert von Karajan and even Richard Strauss.
In 1960, Hansen succeeded Eduard Erdmann at the Hochschule für Musik und Theater Hamburg.
Hansen received the Johannes Brahms Medal of the Hanseatic City of Hamburg, which was also awarded to Günter Wand, Yehudi Menuhin, Felicitas Kukuck and the Hamburg Symphony Orchestra, among others, and was an honorary ring bearer of the city of Lippstadt.
In the 1950s, Hansen made a number of records, initially again for Telefunken (chamber music by Franz Schubert and Antonín Dvořák), then for the Deutsche Grammophon (sonatas by Wolfgang Amadeus Mozart, played on a fortepiano[5]) and finally for Ariola-Eurodisc (Piano Concerto No.