Such a proposal (Maurice Eisenberg was a very highly valued cellist in that period) must have boosted the confidence of the still relatively young composer, all the more so given that at that time Mycielski focused his activity mainly on small line-ups. 

Mycielski began composing the cello preludes most likely immediately after his meeting with Eisenberg; the work was interrupted by a summons to do military service (from September 1933 till January 1934 Mycielski was in Przemyśl, taking part in a course for infantry reserve cadets), with the composer finalising the last two segments of the cycle in March 1934 in Vilnius. Based on the principle of expressive and agogic contrast, the preludes highlight the cello part (extraordinary virtuosic in the fast movements), which engages in a dialogue and co-creates the narrative with the piano part. Interestingly, the theme of the final movement of 4 Piéces pour piano égalant… was used by Mycielski after the war as the first theme of his Silesian Overture.

We do not know whether Maurice Eisenberg performed the pieces in the end (when filling in a questionnaire in 1946, Mycielski mentioned Parisian performances of 4 Piéces pour piano égalant…); what is confirmed is their presentation in Vilnius on 15 April 1934 (Albert Katz – cello, Samuel Chones – piano).