The most indisputable quality of Busoni's pianism was his technique. There were no disagreements in its estimation. Both the rapturous admirers and the fierce detractors of the artist were united in the opinion that the technical achievements of his playing “defy description and comparison with any of the contemporary pianists,” that such technique was “never before possessed by any pianist.” “His technical perfection is fantastic, especially the octaves. There can be no doubt that Busoni has no competition—Rosenthal's technique seems childish after Busoni.” “One needs to play the piano for thirty years to properly appreciate Busoni's playing,” as a famous professor of piano assured the critic Y. Engel.

But even thirty years of piano playing were not always enough to solve the riddles of Busoni's mastery: “Busoni elevated pianism to such head-spinning heights, that even seasoned professionals can hardly make out with the naked eye what precisely he is doing up there.” Accomplished experts, stupefied, threw up their hands: “What this artist has achieved in piano technique borders on the supernatural,” “it seemed thoroughly inconceivable that this was done by one man with two hands,” “it seemed incredible that a mortal sat at the piano!”

Specifically, critics noted “his uncommon playing of scales,” “filigree-like clarity and elegance,” “lightning finger passages,” “magic speed” of octaves, the rapidity and evenness of which were beyond the limits of achievability “even for Teresa Carreño” and other notorious octave players.