Born in Maribor, Slovenia, Slokar decided to dedicate his life to music when he won the first prize as a trombonist at the 7th Yugoslav music contest in Zagreb.
In 1969 he finished his sudies with excellent results at the Music Academy in Ljubjana and then he went to Paris to continue his studies at the Conservatoire National Superieur de Musique. He won several prizes, among others he won the prestigious International ARD Music Competition in Munich.
The Slokar Quartet has toured all over the world and since they started performing together the group has released eleven recordings including a very broad repertoire which ranges from arrangements of early baroque music to first performances of contemporary works.
Many important contemporary composers have been inspired to collaborate intensively with the Slokar Quartet, which has led to a significant expansion of present-day trombone literature.