Armin Janssen, who later called himself Antonio Robledo, studied piano with Carl Seemann at the Musikhochschule in Freiburg from 1948 to 1949. He and Bertold Hummel share a warm friendship and a kindred spirit, which Armin Janssen later alludes to in a letter:

Zurich, 26.12.94

Dear Bertold,
Just like that .... a dear greeting and good wishes for the New Year.
Even though we have lived apart for almost half a century and hardly know each other any more, perhaps something of the common starting points and formative experiences from our cradle, the beautiful Freiburg time, is still there somewhere?

A thousand greetings to you both from both of us. Your Armin

Armin Janssen played the piano part at the premiere of the Sonatina for trumpet and piano op. 1a

Biography

Antonio Robledo (Theatre Dictionary of Switzerland, 2005)