About three weeks after Lev's birth, the family returned to their home in Mitava in the Courland region of the Russian Empire (presently Jelgava, Latvia).
[2] Aronson's sister, Gerda, was born in 1914, the same year Archduke Franz Ferdinand was assassinated and World War I began.
Soon after this, a relative on his mother's side, Nikolai Arnoff, who was a professional cellist, came to Voronezh to give a concert and stayed with the Aronson family.
Aronson studied cello with Paul Berkowitz, a well-known physician and cellist in Riga.
Aronson began studying cello with Klengel and soon gave up law to focus on music.
After a year with Klengel, Lev began his studies with Alfred von Glehn at the Klindworth-Scharwenka Conservatory in Berlin.
Aronson decided to change his name to Lev Arnoff, which sounded more Russian than Jewish in an attempt to escape attention and continue performing.
[9] Aronson found a patroness, Mrs. Daliba Jones, whom he met in Florence through American conductor Vladimir Shavitch, and began to build a successful performing career throughout Europe as a soloist.
[11] During the late 1930s, Aronson also began teaching cello in Riga, awakening a passion for education that would stay with him for the rest of his life.
[12] Between November 29 and December 8, 1941, thousands of Jews living in the Riga Ghetto were taken to the Rumbula forest, shot, and buried in mass graves.
Most Jews from the ghetto or satellite camps passed through Kaiserwald briefly on their way to work assignments within the system.
Aronson and a number of other Jews from Kaiserwald and its subcamps, including his sister, were deported to the Stutthof concentration camp.
Aronson managed to escape and made his way with the help of the Jewish underground through Poland and Germany to the American militarized zone, where he spent nearly two years waiting to be allowed to immigrate to the United States.
Some of the musicians from the Riga ghetto survived the war in the same camps as Aronson; the tenor Gregor Shelkan was one of them.
He founded and conducted the Dal-Hi Chamber Players, a group of young musicians who performed in the United States and abroad in the 1970s.
He also taught a course for the Southern Methodist University Continuing Education program, which introduced adults to western art music.