Left to right:
Ferrucio Busoni, Composer Pianist;
Frederick Stock, Conductor, Chicago Symphony Orchestra;
Wilhelm Middelschulte;
George Hüttner, Conductor, Dortmund Philharmonisches Orchester.

Dortmund, Germany, August 1911, on the occasion of the first performance of Stock's orchestration of Busoni's Fantasie Contrappuntistica.