The London Symphony Orchestra (LSO) is a British symphony orchestra based in London. Founded in 1904, the LSO is the oldest of London's symphony orchestras. The LSO was created by a group of players who left Henry Wood's Queen's Hall Orchestra because of a new rule requiring players to give the orchestra their exclusive services. The LSO itself later introduced a similar rule for its members. From the outset the LSO was organised on co-operative lines, with all players sharing the profits at the end of each season. This practice continued for the orchestra's first four decades.

An orchestra is a large instrumental ensemble typical of classical music, which combines instruments from different families. There are typically four main sections of instruments:String instruments, such as the violin, viola, cello, and double bassWoodwinds, such as the flute, oboe, clarinet, bassoon, and occasional saxophoneBrass instruments, such as the horn, trumpet, trombone, cornet, euphonium, and tubaPercussion instruments, such as the timpani, snare drum, bass drum, cymbals, triangle, tambourine, tam-tam and mallet percussion instruments