-
1948 – 1955
Construction Faculty of the Slovak Technical University in Bratislava, self-taught musician
-
1940s
member of amateur groups, playing jazz and popular music
-
1947 – 1949
member of the Bratislava University Graduate Orchestra
-
1953
two months with the Gustav Brom Orchestra
-
1953 – 1958
played with the Ján Siváček Orchestra
-
1954
the founding of a combo made up of members of the Siváček Orchestra (Juraj Henter, Jozef Jelšovský – trumpet, Karol Ondreička – guitar, J. Štefanovič – piano, Z. Eliška – bass guitar, J. Bauer – drums), which was the first group in Slovakia to specialise in modern jazz (be bop, cool jazz)
-
1959 – 1962
member of the Jaroslav Laifer Orchestra
-
1961 – 1963
participated in Braňo Hronec’s Bratislava Studio, oriented towards the mainstream style
-
1966 – 1967
member of Karol Ondreička’s Combo 4, with which he made a number of radio sessions
-
1970s
an orientation towards popular music; returned to jazz in the 1980s
-
1985
performed in the Hudobné štúdio M television programme (dedicated to the former Bratislava Studio band)
-
1986
Prize for Best Solo Performance at the Slovak Jazz Festival in Žilina (as a soloist for the M Quintet); member of the Bratislava Big Band
-
1992
founded Evergreen-4, oriented towards swing (I. Ťažký – double bass, D. Henčiar – drums, Gabo Jonáš, Pavol Bodnár, Alois Bouda, Ján Hajnal – piano, Ria Hajnalová – vocals)
-
1993 – 1995
member of the Gustav Brom Orchestra (led by Vlado Valovič)
-
1996
member of the Military Artistic Ensemble’s Big Band in Bratislava