[1] Anna Klas was born in Riga into a Jewish family.
Students included: Toivo Peäske, Laine Mets, Virve Lippus, Ada Kuuseoks, Vilma Mallene, Viiva Väinmaa, Valdur Roots, Helju Agur, Aime Karm and others.
From 1944 until 1959, she taught at the Tallinn State Music School (an associate professor since 1946).
In 1941, after the occupation of Estonia by German troops, Eduard Klas was arrested and executed due to his Jewish origins.
Anna Klas escaped the Holocaust by being in the Ural Mountains from 1941 until 1943, as part of the National Art Ensembles of the Estonian SSR, and staying in Yaroslavl from 1943 until 1944.