Long distinguished by its muscular, brass-focused tone and expansive repertoire, the Chicago Symphony Orchestra (CSO) has benefitted from long-term relationships with several music directors. Founded in 1891 by the entrepreneurial conductor Theodore Thomas, the CSO developed an aesthetic rooted in Germanic principles. This continued under his successor, the German-born Frederick Stock, music director from 1905 to 1942. After an unsettled decade in which the orchestra strained to find suitable leadership, Fritz Reiner arrived in 1953, bringing an exacting podium manner, establishing the resident Chicago Symphony Chorus and presiding over a series of now-landmark recordings for RCA Victor (including a trailblazing series of Richard Strauss’ major tone poems). The transitional directorship of Jean Martinon (1963-68) was followed by that of Georg Solti (1969-91), who led the CSO’s first European tours and oversaw the foundation of the orchestra’s composer-in-residence program. Solti cultivated a powerful, flamboyant sound, particularly evident on Decca recordings of Mahler, Bruckner, Beethoven, and Wagner. From 1991 until 2006, the orchestra was led by Daniel Barenboim who continued the orchestra’s international tours and developed its operatic repertoire. Riccardo Muti took up the reins in 2010, and stepped down at the end of the 2023 season. He will continue to make appearances with the orchestra as music director emeritus for life. In 2007, the CSO launched an in-house record label, CSO Resound.