He graduated from the mechanics of textile machines and then worked in NC Tosta Aš.

At that time, he began to be interested in music and formed a band named Apendix.

From 1983 to his death, he was in a relationship with Iveta Bartošová, with whom he founded a singing couple, and with whom he collaborated with extensively.

[1] Sepeši died in a car crash on the evening of 29 July 1985 at the age of 25.

He died along with two other people, at a railway crossing in Františkovy Lázně, when he was heading from Prague home to visit his mother in his hometown of Aš.