He sang at the house for the next two years, portraying eighteen different roles (for example: Faust, Canio in Pagliacci, Laca in Jenůfa, Prince in Rusalka) under the direction of Karel Nedbal.
In 1941 he left Olomouc to join the roster of principal tenors at the Czech National Opera in Prague, singing Jenik again for his first appearance at that house.
[1] Up to this point, Blachut had mostly portrayed lyric tenor parts, but in Prague he began to sing works from the dramatic repertoire, especially in operas by Janáček, Dvořák, and Smetana.
Outside the Czech repertoire, he sang Alfredo in La traviata, Cavaradossi in Tosca, Don José in Carmen, Ferrando in Così fan tutte, Florestan in Fidelio, Hermann in The Queen of Spades, Lensky in Eugene Onegin, Pierre Bezukhov in War and Peace, Radames in Aida, Walther in Die Meistersinger von Nürnberg, and the title roles in Faust and Otello among other roles.
That same year he sang in the world premiere of Jiří Pauer's Zdravý nemocný in Prague after Le malade imaginaire by Molière.