On 14 October 1918, he married Emilia Nidekker, a daughter of the former city mayor and lieutenant colonel in reserve of the Imperial Army.

In August 1919, when the Cossacks retreated and left the city, Przybyszewski stayed in Orsk and took an active part in public and cultural life.

At that time the state policy was to actively 'proletarize' the conservatories, accepting only class-approved students and also striving to restructure the staff and curricula with Marxist standards.

The professors reacted to such reforms negatively; they already were in a bitter conflict with the RAMP due to its obvious harm to musical standards with ideology, vulgarism and dilettantism.

The institution immediately received a vulgar nickname 'Horse school', based on wordplay in Russian, where "Kon" pronounced with the soft last consonant means 'horse'.

In the memoirs of the composer Vissarion Shebalin, Przybyszewski was described as a 'typical intellectual in a bad way: a weak, unreliable person who strived to look nice in everyone's eyes.

'[6] Another professor and a colleague Grigory Kogan [ru] remembered Boleslaw Przybyszewski as a "man of the highest morality, who, unfortunately, was succumbed by the RAMP mottos and tried to shape the conservatory's education accordingly".

[7] On the contrary, the composer Vladimir Shcherbachov mentioned Przybyszewski as a "very interesting man, who led a highly intellectual and intense cultural life, a great dreamer, passionate and dedicated to his ideas up to the extremes.

On 21 August, the Military Collegium of the Supreme Court of the Soviet Union sentenced him to be shot on counts of espionage and planning acts of terrorism.