Dedicated to Michael Mullinar, it was first performed by Sir Adrian Boult and the BBC Symphony Orchestra on April 21, 1948. Within a year it had received some 100 performances, including the U.S. Premiere by the Boston Symphony Orchestra under Serge Koussevitzky on August 7, 1948. Leopold Stokowski gave the first New York performances the following January with the New York Philharmonic and immediately recorded it, declaring that "this is music that will take its place with the greatest creations of the masters." However, Vaughan Williams, very nervous about this symphony, threatened several times to tear up the draft. At the same time, his programme note for the first performance took a defiantly flippant tone.
Perhaps the composer never intended the symphony to be programmatic, but it was inevitable that his post-war audience should associate its disturbing and often violent character with the detonation of the atomic bombs over Hiroshima and Nagasaki. In response to these questions, he is widely quoted as having said, "It never seems to occur to people that a man might just want to write a piece of music". In connection with the last movement, the composer did eventually suggest that a quotation from Act IV of Shakespeare's The Tempest comes close to the music’s meaning: "We are such stuff / As dreams are made on; and our little life / Is rounded with a sleep."
The Symphony is noteworthy for its unusually discordant harmonic language, reminiscent in approach if not in technique of his F Minor Symphony from over a decade earlier, and for its inclusion of a tenor saxophone among the woodwinds. In several respects this symphony marks the beginning of Vaughan Williams’s experiments with orchestration that so characterise his late music.
The symphony is in four linked movements (i.e. one movement leads straight into the next, with no pause between them), and includes a number of ideas that return in various guises throughout the symphony, for example the use of simultaneous chords a half-step apart, or the short-short-long rhythmic figure.