Sondeckis was born in Šiauliai in 1928. He graduated from the Lithuanian Academy of Music and Theatre (Vilnius Conservatory) as a violinist with Alexander Livontas in 1952 and studied conducting with Igor Markevich. Sondeckis was a member of the Department of String Instruments at the Lithuanian SSR State Conservatoire. Sondeckis began conducting in 1955 and started at the Student Orchestra of the National M.K. Čiurlionis School of Art. He became a teacher at the Lithuanian Academy in 1959 and became a professor there in 1976. In 1960, Sondeckis founded the Lithuanian Chamber Orchestra in...
