Sondeckis was born in Ĺ iauliai 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. Äiurlionis School of Art. He became a