Timed to coincide with the 70th anniversary of Sir Adrian Boult’s appointment as Principal Conductor of the London Philharmonic Orchestra, the five-volume set “Sir Adrian Boult: A Musical Legacy” celebrates the long relationship that the conductor enjoyed with the LPO from his tenure as Principal Conductor (1950–57) to his retirement in 1978. The series explores Boult as a great conductor of Germanic repertoire, the music of his contemporaries, and as a champion of British music. An entire disc is devoted to ballet, a genre in which Boult honed his early conducting skills both with the Royal Opera House and Ballets Russes.