Karl Brückner was a German violinist and music educator, born in Gothenburg on May 5, 1893. His father, Gustav Julius Brückner, was a German violinist and music educator who worked in Sweden for a time. Karl was also a grandson of historian Alexander Brückner and a nephew of meteorologist Eduard Brückner.
He studied violin with his father and performed in school concerts from the age of four or five. From 1901, he studied at the Leipzig Conservatory with Hans Sitt. During the 1900s and 1910s, he toured Germany, England, and Scandinavian countries. He later studied musicology at the universities of Leipzig and Munich, completing a doctoral dissertation in Munich in 1920.
From 1921 to 1926, Brückner was a professor at the Baden Higher School of Music. He then served as concertmaster of an orchestra in Frankfurt from 1926 to 1929 and worked in Hamburg from 1929 to 1935. He wrote articles for music periodicals on the history and psychology of violin playing.
Brückner taught at the Riga Conservatory from 1945 to 1960 and also gave private lessons. He performed in chamber concerts and on the radio. His students included his grandson, violinist Gidon Kremer, whose first teacher he was, and conductor Toviy Lifshits. In lessons, Brückner encouraged students to explore different ways of shaping a musical passage, often demonstrating alternatives on the violin.