Formed in 1945 by record producer Walter Legge, the London-based Philharmonia Orchestra has consistently been a world-class symphony. It began with ad hoc membership, over time evolving into a working institution with extended runs by conductors as distinguished as Herbert von Karajan, Otto Klemperer, Riccardo Muti and Esa-Pekka Salonen, plus countless guest maestros. Early on, the Philharmonia focused on German and Austrian repertoire, eventually expanding under Muti. Lorin Maazel's direction of Mahler's 8th Symphony is full of bravado, while a performance of Beethoven's Piano Concerto No. 4 with pianist Min-Jung Kym balances weight and lightness.