Renowned for crisply disciplined performances of 18th-century compositions in historically appropriate style, using the types of instruments that existed when the music was originally written, this German ensemble has, in recent years, extended its repertoire to the late-Romantic operas of Wagner. Founded in 1985, Concerto Köln (CK) is a self-governed body of musicians. While many of its performances and recordings have been directed from the leader’s chair (whether the lead violinist or harpsichord player), from 1987 the group worked extensively with the French conductor René Jacobs; his work with them includes recordings of Handel’s opera Giulio Cesare (1991) and a dramatically cogent account of his oratorio Saul (2005) in addition to lively accounts of Mozart’s Così fan tutte (1999) and Le nozze di Figaro (2004). CK began recording early-Romantic repertoire with Mendelssohn’s String Symphonies, followed by Field’s Piano Concertos Nos 2 & 3 with soloist Andreas Staier (1999). The ensemble’s care in finding or reviving authentic instruments for its performances is typified by its 2014 recording of Bach’s Brandenburg Concertos, for which, in response to the composer’s specification of a Flauti d’echo for Concerto No. 4, a special double recorder—a long-lost instrument—was reconstructed. The conductor Kent Nagano, with whom CK has collaborated extensively since 2011, was appointed its honorary conductor in 2019 and has since embarked on a project with the ensemble to give a historically informed performance of Wagner’s opera cycle The Ring of the Nibelung.